Students taking Multivariable Calculus (Calculus III) can download the complete textbook “Calculus Volume 3” by Gilbert Strang and Edwin “Jed” Herman, free as a PDF from OpenStax. It is a traditional, example-and-exercise-driven calculus text — every section works through several fully-solved examples before a large practice-problem set, and every chapter closes with a Key Terms, Key Equations, and Key Concepts review before its Chapter Review Exercises.
This is Volume 3, the final volume of OpenStax’s three-volume calculus series, covering the full Multivariable Calculus course: vectors and vector-valued functions, differentiation and integration of multivariable functions, vector calculus, and second-order differential equations. It is a noticeably more advanced book than Volumes 1 and 2, and is designed to stand alone, so Calculus Volume 2 is not required beyond general familiarity with Calculus II material.
Book Overview
| Course | Multivariable Calculus (Calculus III) |
| Degree Programs | BS Mathematics, BSCS, Engineering — typically a third-semester requirement |
| Level | University — third semester (upper-level calculus) |
| Edition | OpenStax edition — published March 30, 2016 |
| Author | Gilbert Strang, Edwin “Jed” Herman |
| Structure | 7 chapters, from a parametric/polar review through vectors, multivariable differentiation, multiple integration, vector calculus, and second-order differential equations |
| Exercises | Every section ends with a substantial practice-problem set, and every chapter closes with Key Terms, Key Equations, Key Concepts, and a full Chapter Review Exercises set |
| Language | English |
| License | Creative Commons Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA 4.0) — Model: Link-only |
| Format | Free PDF and web/HTML reader; also available as a low-cost print edition through third-party printers |
Chapter List
Chapter 1: Parametric Equations and Polar Coordinates
Difficulty: Medium · Multivariable Calculus · Key topics: parametric equations, calculus of parametric curves, polar coordinates, area and arc length in polar coordinates, conic sections
Volume 3 opens by rebuilding parametric and polar tools from Volume 2, so that this book can stand on its own as a complete Multivariable Calculus course. Parametric equations describe a curve, or the position of a moving particle, using a third variable (usually t) that both x and y depend on. The chapter extends derivatives, arc length, and surface area to parametric curves, then introduces polar coordinates as an alternative coordinate system particularly suited to circular and spiral shapes. It closes with area and arc length formulas adapted to polar coordinates, and a unified focus-directrix review of the conic sections — all of it laying the two-dimensional groundwork the rest of the book generalizes into three dimensions.
Key Points:
- A parametric curve is given by x=f(t), y=g(t); it can trace loops, cusps, and self-intersections that no single function y=h(x) could represent.
- dy/dx for a parametric curve is (dy/dt)/(dx/dt), not dy/dt alone — the chain rule connects the two parametric derivatives to the curve’s actual slope.
- Polar coordinates (r,θ) locate a point by distance from the origin and angle from the positive x-axis; x=r cosθ, y=r sinθ translate between polar and rectangular forms.
- Area enclosed by a polar curve is (1/2)∫r²dθ, not ∫r dθ — a common point of confusion since it looks unlike the rectangular area formula.
- Arc length in polar coordinates is ∫√(r²+(dr/dθ)²)dθ, derived the same way as parametric arc length once r(θ) is treated as a parametric curve in disguise.
- All three conic sections (ellipse, parabola, hyperbola) can be written with a single unified polar equation using eccentricity e: e<1 gives an ellipse, e=1 a parabola, e>1 a hyperbola.
Practice Tip: If you’ve just finished Calculus Volume 2, this chapter is a fast review, not new material — skim it to confirm fluency and move quickly to Chapter 2, where the book’s genuinely new (three-dimensional) content begins.
Common Mistake: Using ∫r dθ instead of (1/2)∫r² dθ for polar area. This mirrors a genuinely different derivation (summing infinitesimal circular sectors, not rectangles) from rectangular area, and mixing the two formulas up is a common error carried over from Volume 2.
Important Questions:
- Eliminate the parameter from x=t², y=2t (for all real t) to find the equation of the curve in x and y. From y=2t, t=y/2; substituting into x=t² gives x=(y/2)²=y²/4, i.e. y²=4x — a sideways parabola.
- Find the area enclosed by the polar curve r=2 (a circle of radius 2) using the polar area formula, and confirm it against the familiar circle-area formula. Area = (1/2)∫02π 2² dθ = (1/2)(4)(2π) = 4π, which matches πr² = π(2)² = 4π exactly, as expected for a full circle of radius 2.
Chapter 2: Vectors in Space
Difficulty: Medium · Multivariable Calculus · Key topics: vectors in the plane, vectors in three dimensions, the dot product, the cross product, equations of lines and planes in space, quadric surfaces, cylindrical and spherical coordinates
Chapter 2 is where the book genuinely becomes three-dimensional. It introduces vectors as objects with both magnitude and direction, first in the familiar plane and then in three-dimensional space, and develops the two products that make vector algebra useful: the dot product, which measures how much two vectors point the same way (and gives angles and projections), and the cross product, which produces a new vector perpendicular to both inputs (and gives areas and torque-like quantities). The chapter uses these tools to write equations for lines and planes in space, catalogs the standard quadric surfaces (ellipsoids, paraboloids, hyperboloids), and closes with cylindrical and spherical coordinates — two coordinate systems that will make later integrals dramatically simpler for curved regions.
Key Points:
- A vector has both magnitude and direction; two vectors are equal exactly when they have the same magnitude and direction, regardless of where they’re drawn.
- The dot product u·v = u1v1+u2v2+u3v3 = |u||v|cosθ measures alignment between two vectors; u·v=0 means the vectors are orthogonal (perpendicular).
- The cross product u×v produces a vector perpendicular to both u and v, with magnitude |u||v|sinθ equal to the area of the parallelogram they span — it is defined only in three dimensions.
- A line in space is given by a point plus a direction vector (parametrically); a plane is given by a point plus a normal vector, using the fact that any vector in the plane is orthogonal to the normal.
- The standard quadric surfaces (ellipsoid, elliptic paraboloid, hyperbolic paraboloid, cone, hyperboloid of one/two sheets) are each recognized from the signs and powers in their equation, the same way conic sections are recognized in two dimensions.
- Cylindrical coordinates (r,θ,z) extend polar coordinates by adding a height; spherical coordinates (ρ,θ,φ) use a distance from the origin and two angles — both dramatically simplify equations and later integrals for regions with circular or spherical symmetry.
Practice Tip: Whenever a problem gives you two vectors and asks for an angle or a check of perpendicularity, reach for the dot product; whenever it asks for an area, a normal vector, or a vector perpendicular to two given ones, reach for the cross product. Keeping this division clear from the start prevents most vector-algebra mix-ups later in the chapter.
Common Mistake: Treating the cross product as commutative. u×v = −(v×u), not u×v = v×u — reversing the order of a cross product flips the sign (and the direction) of the result, unlike the dot product, which genuinely is commutative.
Important Questions:
- Find the dot product of u=(1,2,3) and v=(4,−5,6), and state whether they are orthogonal. u·v = (1)(4)+(2)(−5)+(3)(6) = 4−10+18 = 12. Since 12≠0, the vectors are not orthogonal.
- A plane passes through the point (1,0,0) with normal vector n=(2,1,−1). Write its equation. Using n·(r−r₀)=0: 2(x−1)+1(y−0)−1(z−0)=0, which simplifies to 2x+y−z=2.
Chapter 3: Vector-Valued Functions
Difficulty: Medium · Multivariable Calculus · Key topics: vector-valued functions and space curves, calculus of vector-valued functions, arc length and curvature, motion in space
Chapter 3 combines the vectors of Chapter 2 with the calculus of earlier volumes to describe curves and motion in space directly. A vector-valued function r(t)=(x(t),y(t),z(t)) traces a curve through space as t varies, generalizing the parametric curves of Chapter 1 into three dimensions. The chapter develops derivatives and integrals of vector-valued functions component-by-component, uses them to define arc length and curvature (how sharply a curve bends), and closes with motion in space — where the derivative of position gives velocity, and the derivative of velocity gives acceleration, letting the chapter model real trajectories such as projectile motion and, in a signature worked example, Kepler’s laws of planetary motion.
Key Points:
- A vector-valued function r(t)=(x(t),y(t),z(t)) traces a space curve; its derivative r′(t) is a tangent vector to the curve at each point, found by differentiating each component separately.
- Arc length of a space curve is ∫|r′(t)|dt — the same idea as parametric arc length in Chapter 1, generalized to three components.
- Curvature κ measures how sharply a curve bends; a straight line has curvature 0, and a tight circle has high curvature (specifically κ=1/radius for a circle).
- For motion in space, velocity v(t)=r′(t) and acceleration a(t)=v′(t)=r″(t) — the same derivative relationships from single-variable calculus, applied component-by-component to a position vector.
- Acceleration can be split into tangential and normal components: the tangential component changes speed, and the normal component changes direction — this decomposition is what explains why a car needs less engine force to hold a curve at constant speed than to also accelerate through it.
- Kepler’s laws of planetary motion (elliptical orbits, equal areas in equal times, and the period-distance relationship) can be derived from Newton’s law of gravitation using exactly the vector calculus tools this chapter develops.
Practice Tip: When a motion-in-space problem gives you acceleration and asks for position, integrate twice component-by-component just as you would with a single-variable function — and don’t forget that each integration introduces its own vector constant of integration, found from the initial velocity and initial position given in the problem.
Common Mistake: Confusing speed (a scalar, |v(t)|) with velocity (a vector, v(t)). A problem asking “how fast” wants the magnitude of the velocity vector, not the velocity vector itself — a very common point-loss on exams covering this chapter.
Important Questions:
- Find r′(t) for r(t) = (t², sin t, et). Differentiate each component separately: r′(t) = (2t, cos t, et).
- An object has position r(t)=(3t, 4t, 0). Find its velocity and speed. v(t)=r′(t)=(3,4,0), a constant vector, so speed = |v(t)| = √(3²+4²+0²) = √25 = 5, constant for all t.
Chapter 4: Differentiation of Functions of Several Variables
Difficulty: Hard · Multivariable Calculus · Key topics: functions of several variables, limits and continuity, partial derivatives, tangent planes and linear approximations, the chain rule, directional derivatives and the gradient, maxima/minima problems, Lagrange multipliers
Chapter 4 extends differentiation itself to functions of more than one variable — quantities like temperature that depend on both location and time, or profit that depends on both units sold and advertising spend. Limits and continuity are redefined for multivariable functions, and partial derivatives measure the rate of change with respect to one variable while holding the others fixed. The chapter builds up to the gradient, a vector of partial derivatives that points in the direction of steepest increase, and uses it to find directional derivatives in any direction, not just along the coordinate axes. It closes with two optimization techniques: ordinary maxima/minima analysis for unconstrained problems, and Lagrange multipliers for finding extrema subject to a constraint.
Key Points:
- A partial derivative ∂f/∂x treats every variable except x as a constant and differentiates normally — the mechanics are identical to single-variable differentiation, applied one variable at a time.
- A function of two variables is continuous at a point only if its limit is the same approaching from every direction — unlike one variable (only two directions to check), there are infinitely many paths of approach in two or more variables, making multivariable continuity genuinely harder to verify.
- The tangent plane to z=f(x,y) at a point uses both partial derivatives: z = f(a,b) + fx(a,b)(x−a) + fy(a,b)(y−b) — the direct two-variable generalization of a tangent line.
- The multivariable chain rule tracks every path from an independent variable to the final output through intermediate variables, summing a term for each path — more bookkeeping than the single-variable chain rule, but the same underlying idea.
- The gradient ∇f = (fx, fy, fz) points in the direction of steepest increase of f, and the directional derivative in any direction u is ∇f·u — the dot product connects Chapter 2’s vectors directly to multivariable derivatives.
- Lagrange multipliers find extrema of f(x,y) subject to a constraint g(x,y)=c by solving ∇f = λ∇g together with the constraint itself — geometrically, the level curves of f and g are tangent at the constrained extremum.
Practice Tip: When checking whether a multivariable limit exists, always try at least two different paths of approach (e.g. along y=0 and along y=x) before concluding it does — if the two paths give different limiting values, the limit does not exist, and you’re done. Only reach for a full epsilon-delta or polar-coordinate argument once several paths agree.
Common Mistake: Assuming a critical point found by setting both partial derivatives to zero is automatically a maximum or minimum. Just as in single-variable calculus a critical point can be an inflection point, in two variables it can be a saddle point — the Second Partials Test (using fxx, fyy, and fxy) is required to classify it, and skipping this step is the single most common error in this chapter’s optimization problems.
Important Questions:
- Find ∂f/∂x and ∂f/∂y for f(x,y) = x²y + 3xy². ∂f/∂x = 2xy + 3y² (treating y as constant); ∂f/∂y = x² + 6xy (treating x as constant).
- Use Lagrange multipliers to find the extremum of f(x,y)=xy subject to the constraint x+y=10. ∇f=(y,x), ∇g=(1,1), so y=λ and x=λ, giving x=y. With x+y=10, x=y=5, so the extremum is f(5,5)=25 (a maximum, by inspection of nearby constrained values).
Chapter 5: Multiple Integration
Difficulty: Hard · Multivariable Calculus · Key topics: double integrals over rectangular regions, double integrals over general regions, double integrals in polar coordinates, triple integrals, triple integrals in cylindrical and spherical coordinates, calculating centers of mass and moments of inertia, change of variables in multiple integrals
Chapter 5 extends the definite integral to functions of two and three variables, letting it compute volumes, masses, and centroids of genuinely three-dimensional objects. It begins with double integrals over simple rectangular regions, then general regions bounded by curves, before showing how switching to polar coordinates dramatically simplifies integrals over circular regions — the same motivation behind cylindrical and spherical coordinates for triple integrals over three-dimensional regions with circular or spherical symmetry. The chapter applies these tools to physical quantities (centers of mass, moments of inertia for objects with varying density) and closes with a general change-of-variables technique (the Jacobian) that formalizes why switching coordinate systems is legitimate and shows how to do it for any substitution, not just the standard ones.
Key Points:
- A double integral ∫∫R f(x,y) dA is evaluated as an iterated integral — integrate with respect to one variable first (treating the other as constant), then the result with respect to the second variable.
- For a general (non-rectangular) region, the order of integration determines the bounds on the inner integral, which typically depend on the outer variable — sketching the region first is essential to get these bounds right.
- Switching to polar coordinates for a double integral requires the extra factor of r: dA becomes r dr dθ — forgetting this factor is the single most common error when converting.
- A triple integral ∫∫∫E f(x,y,z) dV computes a three-dimensional accumulation (volume when f=1, or mass when f is a density function) via three nested integrations.
- Cylindrical coordinates add the factor r (dV = r dz dr dθ), and spherical coordinates add the factor ρ²sinφ (dV = ρ²sinφ dρ dφ dθ) — both simplify integrals dramatically for regions with the matching symmetry.
- The Jacobian generalizes the polar/cylindrical/spherical extra factors to ANY change of variables: for a substitution (x,y)→(u,v), dA becomes |∂(x,y)/∂(u,v)| du dv, where the Jacobian determinant measures how the substitution stretches or shrinks area.
Practice Tip: Before setting up any multiple integral, sketch the region of integration and shade it — most errors in this chapter come from getting the bounds of an iterated integral wrong, not from the integration itself, and a clear picture makes the correct bounds almost obvious.
Common Mistake: Forgetting the extra r (cylindrical) or ρ²sinφ (spherical) factor when converting a triple integral to a curved coordinate system. This factor comes from how volume elements distort under the coordinate change, exactly like the Jacobian in the chapter’s final section — omitting it gives a numerically wrong answer even when every other step is correct.
Important Questions:
- Set up (but do not evaluate) the iterated integral for ∫∫R xy dA where R is the rectangle 0≤x≤2, 0≤y≤3. ∫03∫02 xy dx dy (or the equivalent order dy dx first) — since R is rectangular, the bounds are simply constants in either order.
- Convert the double integral ∫∫R (x²+y²) dA to polar coordinates, where R is the disk of radius 3 centered at the origin. Using x²+y²=r² and dA=r dr dθ: ∫02π∫03 r²·r dr dθ = ∫02π∫03 r³ dr dθ.
Chapter 6: Vector Calculus
Difficulty: Hard · Multivariable Calculus · Key topics: vector fields, line integrals, conservative vector fields, Green’s Theorem, divergence and curl, surface integrals, Stokes’ Theorem, the Divergence Theorem
Chapter 6 is the capstone of the calculus sequence, unifying nearly everything before it into a single framework for integrating over vector fields — models of phenomena like electromagnetic fields, gravitational fields, or fluid velocity fields. Line integrals integrate along a curve through a vector field (generalizing ordinary integration to curved paths); conservative vector fields (those that are gradients of some potential function) make these integrals path-independent, a fact the chapter proves and exploits. Green’s Theorem connects a line integral around a closed curve to a double integral over the region it encloses, and this same pattern generalizes to three dimensions via surface integrals and two capstone theorems: Stokes’ Theorem (relating a surface integral of curl to a line integral around its boundary) and the Divergence Theorem (relating a triple integral of divergence to a surface integral over the enclosing surface).
Key Points:
- A vector field F assigns a vector to every point in space (or the plane); a line integral ∫C F·dr sums the component of F along the direction of travel over the curve C.
- A vector field F is conservative if F=∇f for some scalar potential function f — for a conservative field, the Fundamental Theorem for Line Integrals makes ∫C F·dr depend only on the curve’s endpoints, not the path taken.
- Green’s Theorem converts a line integral around a simple closed curve C into a double integral over the region D it encloses: ∮C P dx + Q dy = ∫∫D (∂Q/∂x − ∂P/∂y) dA.
- Divergence div F measures a vector field’s tendency to spread out (a source) or converge (a sink) at a point; curl F measures its tendency to rotate — both are computed from partial derivatives of F’s components.
- Stokes’ Theorem generalizes Green’s Theorem to a surface in three dimensions: the surface integral of curl F over a surface equals the line integral of F around the surface’s boundary curve.
- The Divergence Theorem generalizes Green’s Theorem the other way: the triple integral of div F over a solid region equals the flux (surface integral) of F over the region’s entire enclosing surface.
Practice Tip: Before computing any line or surface integral directly, check whether the vector field is conservative (a quick partial-derivatives test, ∂P/∂y = ∂Q/∂x in two dimensions) or whether Green’s/Stokes’/the Divergence Theorem applies to the specific curve or surface given — a huge fraction of this chapter’s hardest-looking problems become trivial once the right shortcut theorem is recognized, instead of grinding through a direct parametrization.
Common Mistake: Applying Green’s Theorem, Stokes’ Theorem, or the Divergence Theorem without checking their hypotheses first — Green’s Theorem requires a simple (non-self-intersecting), closed, positively-oriented curve, and the Divergence Theorem requires a closed surface. Using these theorems on a curve or surface that doesn’t meet the requirements gives a confidently wrong answer with no warning.
Important Questions:
- Is the vector field F(x,y) = (2xy, x²) conservative? If so, find a potential function. ∂P/∂y = 2x and ∂Q/∂x = 2x are equal, so F is conservative. A potential function is f(x,y) = x²y + C, since ∂f/∂x=2xy and ∂f/∂y=x².
- State what the Divergence Theorem equates, in words, and name one physical quantity it’s typically used to compute. The Divergence Theorem equates the triple integral of a vector field’s divergence over a solid region to the total flux of the field out through the region’s boundary surface; it is typically used to compute the total outward flux of a field (e.g. fluid flow, or electric flux in Gauss’s Law) without directly parametrizing and integrating over a complicated enclosing surface.
Chapter 7: Second-Order Differential Equations
Difficulty: Medium · Multivariable Calculus · Key topics: second-order linear equations, nonhomogeneous linear equations, applications, series solutions of differential equations
The closing chapter returns to differential equations (introduced for first-order equations in Calculus Volume 2) and extends the theory to second-order linear equations — equations involving a function’s second derivative, which arise constantly in physics and engineering. The chapter first solves the homogeneous case (constant-coefficient equations with no external forcing term) by finding roots of a characteristic equation, then extends to the nonhomogeneous case, where a forcing term requires finding one particular solution in addition to the homogeneous solutions. A dedicated applications section grounds the theory in real second-order systems — RLC electrical circuits and spring-mass systems like a motorcycle’s shock absorbers — before the chapter closes with series solutions, a technique for differential equations too complex for the earlier closed-form methods.
Key Points:
- A second-order linear homogeneous equation ay″+by′+cy=0 with constant coefficients is solved via its characteristic equation ar²+br+c=0; the nature of the roots (real distinct, repeated, or complex) determines the form of the general solution.
- Complex roots r=α±βi in the characteristic equation produce oscillating solutions of the form eαx(c1cosβx + c2sinβx) — the mathematical origin of every oscillating physical system this chapter models.
- For a nonhomogeneous equation ay″+by′+cy=g(x), the general solution is the homogeneous solution plus any one particular solution — found via undetermined coefficients (guessing a form matching g(x)) or variation of parameters (a more general but more computational method).
- A damped spring-mass system (or an RLC circuit, its exact electrical analogue) is modeled by a second-order equation whose behavior — overdamped, critically damped, or underdamped (oscillating) — is determined entirely by the sign of the characteristic equation’s discriminant.
- Series solutions represent y as a power series ∑anxn and substitute into the differential equation to find a recurrence relation for the coefficients — necessary when a differential equation has no elementary closed-form solution.
- This chapter closes not just Volume 3 but the entire three-volume OpenStax Calculus sequence, connecting directly back to the power series techniques of Calculus Volume 2’s Chapter 6.
Practice Tip: Before solving any second-order linear equation, write down its characteristic equation and classify its roots (real distinct, repeated, or complex) first — the solution’s form follows immediately and mechanically from that classification, so getting the roots right is most of the problem.
Common Mistake: Forgetting to add the particular solution when solving a nonhomogeneous equation, and stopping at just the homogeneous solution. The homogeneous solution alone satisfies ay″+by′+cy=0, not the actual equation with its nonzero right-hand side — the general solution always needs both pieces added together.
Important Questions:
- Solve the characteristic equation for y″−5y′+6y=0, and give the general solution. r²−5r+6=0 factors as (r−2)(r−3)=0, giving r=2 and r=3 (real, distinct roots), so the general solution is y = c₁e2x + c₂e3x.
- Classify the roots of the characteristic equation for y″+4y=0, and describe the resulting behavior. r²+4=0 gives r=±2i (purely imaginary, complex roots with α=0), so the general solution is y = c₁cos(2x) + c₂sin(2x) — pure, undamped oscillation, the signature behavior of complex roots with zero real part.
Download Calculus Volume 3 PDF (Free)
This book is free from its official source, OpenStax. Click below to download the complete PDF — a free web-based reader edition (with per-section, linkable pages) is also available on the OpenStax site if you’d rather read online.
↓ Download PDFHow to Study This Book
Read the seven chapters in order — each one leans directly on the last. Chapter 1 (Parametric Equations and Polar Coordinates) rebuilds Volume 2’s closing chapter, so if you’ve just finished Volume 2 you can move through it quickly as review before Chapter 2’s genuinely new (three-dimensional) material begins.
Chapters 2 and 3 (Vectors in Space, Vector-Valued Functions) build the vector toolkit — the dot product, cross product, and vector-valued derivatives — that every later chapter in this book depends on. Do not rush these; a shaky grasp of the dot and cross products is the single most common reason students struggle with Chapters 4 through 6.
Chapter 4 (Differentiation of Functions of Several Variables) is where the course becomes conceptually distinct from single-variable calculus. Work through partial derivatives and the chain rule carefully before attempting Lagrange multipliers (4.8) — it is the chapter’s hardest section and depends on everything before it.
Chapter 5 (Multiple Integration) is usually the most computation-heavy chapter in the book. Sketch every region of integration before setting up bounds, and don’t attempt cylindrical/spherical triple integrals (5.5) until double integrals in polar coordinates (5.3) are comfortable — the extra-factor idea (r, or ρ²sinφ) is the same in both places.
Chapter 6 (Vector Calculus) is the capstone of the entire three-volume series and the most theorem-dense chapter in the book — Green’s, Stokes’, and the Divergence Theorem. Most courses spend more time here than the chapter’s length suggests; budget accordingly.
Chapter 7 (Second-Order Differential Equations) is largely independent of Chapters 2–6 and returns to the differential-equations thread from Calculus Volume 2’s Chapter 4 — some Multivariable Calculus syllabi cover it in full, others treat it as optional or move it to a dedicated differential equations course. Check your syllabus.
This is Volume 3, the final volume of a three-volume OpenStax series. Chapter 1 intentionally overlaps with the end of Calculus Volume 2 (Parametric Equations and Polar Coordinates) so this book stands alone; Calculus Volume 1 and Volume 2 cover the earlier Calculus I and Calculus II material, not needed to start this book beyond general calculus fluency.
Used In These Programs
This book is used for the Multivariable Calculus course in: BS Mathematics, BSCS, and Engineering programs. Browse all Calculus books or all Mathematics books.
Who Should Read This
Calculus Volume 3 is written for a student who has completed both Calculus I and Calculus II and is moving into Multivariable Calculus — it assumes solid fluency with derivatives, integrals, and series, and rebuilds parametric/polar tools from Volume 2’s closing chapter, so it does not require Calculus Volume 2 specifically as long as you already know that material. It is a noticeably more advanced and abstract book than Volumes 1 and 2, aimed specifically at BS Mathematics, engineering, and computer science students whose programs require a third calculus course — not a general-education audience. Its example-and-exercise-driven style, with large practice sets at the end of every section, suits a student who learns by working through many worked examples and problems, and its free web reader links every term to its definition.
Applicable Universities
This book is useful for students at Pakistani universities offering BS Mathematics, BSCS, or Engineering programs, including Punjab University, Virtual University, COMSATS, FAST, UET, NUST, and other HEC-recognized institutions.
FAQs
Is Calculus Volume 3 free?
Yes. OpenStax publishes it under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA 4.0) licence, free to read online, download as a PDF, or print. OpenStax’s own required attribution line is simply “Access for free at openstax.org.”
Do I need to read Calculus Volume 2 before this book?
You need to already know Calculus II material (integration techniques, series, and especially parametric equations and polar coordinates), but you don’t need Volume 2 specifically as the source — Chapter 1 of this volume rebuilds parametric and polar tools from scratch as a review. If your Calculus II course used a different textbook entirely, that’s fine, as long as the material itself is familiar.
Why does Chapter 1 of this book look the same as the end of Volume 2?
This is intentional, not an error. OpenStax designs each volume of its Calculus series to stand alone, so Volume 3’s Chapter 1 (Parametric Equations and Polar Coordinates) deliberately repeats the same material as Volume 2’s Chapter 7. If you’ve just finished Volume 2, you can treat this chapter as a fast review before Chapter 2’s new (three-dimensional) material begins.
Is this the same as “Calculus III” or “Multivariable Calculus” at my university?
Yes — Calculus Volume 3 covers exactly the standard Multivariable Calculus / Calculus III syllabus: vectors and vector-valued functions, partial derivatives, multiple integrals, vector calculus (Green’s, Stokes’, and the Divergence Theorem), and second-order differential equations. The name varies by institution, but the content matches the third calculus course required by most BS Mathematics and Engineering programs.
Which edition is this, and is it still current?
The original OpenStax edition, published March 30, 2016. Calculus content doesn’t change the way a programming or web-development textbook does — vector calculus and multiple integration are the same today as in 2016 — so this edition remains the standard, actively distributed OpenStax text with no newer edition to prefer.
Can I use this commercially or must it stay non-commercial?
The NC (NonCommercial) term in the licence means the book itself cannot be resold or otherwise used commercially without OpenStax’s permission — reading, downloading, printing a personal copy, and classroom use are all fine and exactly what the licence is meant for.
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Calculus Volume 3 completes OpenStax’s three-volume calculus series with Multivariable Calculus, and its large, traditional practice-problem sets make it a strong match for students who learn best by working through many worked examples. Browse more Mathematics books for the rest of your semester.
Calculus Volume 3, by Gilbert Strang and Edwin “Jed” Herman. OpenStax, Rice University. Free under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 licence. Access for free at https://openstax.org/details/books/calculus-volume-3