All practice topics

Antiderivatives

17 practice questions with full worked solutions. Free, no account needed.

Problems & worked solutions

Problem #0122 International

Problem 1Antiderivatives

5dx\displaystyle\int 5 \, dx equals:

Show answer & worked solution
  1. A. 00
  2. B. 55
  3. C. 5x+C5x + C✓ correct
  4. D. x25+C\dfrac{x^2}{5} + C

cdx=cx+C\int c \, dx = cx + C. So 5dx=5x+C\int 5 \, dx = 5x + C.

Problem #0123 International

Problem 2Antiderivatives

exdx\displaystyle\int e^x \, dx equals:

Show answer & worked solution
  1. A. ex+1+Ce^{x+1} + C
  2. B. xex+Cx e^x + C
  3. C. ex+Ce^x + C✓ correct
  4. D. lnx+C\ln x + C

The exponential is its own antiderivative: exdx=ex+C\int e^x \, dx = e^x + C.

Problem #0121 International

Problem 3Antiderivatives

x3dx\displaystyle\int x^3 \, dx equals:

Show answer & worked solution
  1. A. 3x2+C3x^2 + C
  2. B. x43+C\dfrac{x^4}{3} + C
  3. C. x44+C\dfrac{x^4}{4} + C✓ correct
  4. D. 4x4+C4x^4 + C

x3dx=x44+C\int x^3 \, dx = \dfrac{x^4}{4} + C.

Problem #0001 International

Problem 4Definite Integrals

Evaluate 0π/2sin3(x)cos(x)dx\int_0^{\pi/2} \sin^3(x)\cos(x)\,dx.

Show answer & worked solution
  1. A. 18\dfrac{1}{8}
  2. B. 14\dfrac{1}{4}✓ correct
  3. C. 38\dfrac{3}{8}
  4. D. 12\dfrac{1}{2}

Let u=sinxu = \sin x, du=cosxdxdu = \cos x\,dx. The integral becomes 01u3du=[u44]01=14\int_0^1 u^3\,du = \left[\dfrac{u^4}{4}\right]_0^1 = \dfrac{1}{4}.

Problem #0124 International

Problem 5Antiderivatives

1xdx\displaystyle\int \dfrac{1}{x} \, dx (for x>0x > 0) equals:

Show answer & worked solution
  1. A. 1x2+C\dfrac{1}{x^2} + C
  2. B. 1x2+C-\dfrac{1}{x^2} + C
  3. C. lnx+C\ln x + C✓ correct
  4. D. x00+C\dfrac{x^0}{0} + C

dxx=lnx+C\int \dfrac{dx}{x} = \ln|x| + C. For x>0x > 0: lnx+C\ln x + C.

Problem #0126 International

Problem 6Antiderivatives

xexdx\displaystyle\int x e^x \, dx equals:

Show answer & worked solution
  1. A. x22ex+C\dfrac{x^2}{2}e^x + C
  2. B. ex+Ce^x + C
  3. C. (x1)ex+C(x - 1)e^x + C✓ correct
  4. D. xex+Cx e^x + C

xexdx=xexexdx=xexex+C=(x1)ex+C\int x e^x \, dx = x e^x - \int e^x \, dx = x e^x - e^x + C = (x - 1) e^x + C.

Problem #0128 International

Problem 7Antiderivatives

1x2+1dx\displaystyle\int \dfrac{1}{x^2 + 1} \, dx equals:

Show answer & worked solution
  1. A. ln(x2+1)+C\ln(x^2 + 1) + C
  2. B. 2xx2+1+C\dfrac{2x}{x^2 + 1} + C
  3. C. arctanx+C\arctan x + C✓ correct
  4. D. arcsinx+C\arcsin x + C

A standard antiderivative: dx1+x2=arctanx+C\int \dfrac{dx}{1 + x^2} = \arctan x + C.

Problem #0127 International

Problem 8Antiderivatives

2xcos(x2)dx\displaystyle\int 2x \cdot \cos(x^2) \, dx equals:

Show answer & worked solution
  1. A. sin(2x)+C\sin(2x) + C
  2. B. 2sin(x2)+C2\sin(x^2) + C
  3. C. sin(x2)+C\sin(x^2) + C✓ correct
  4. D. cos(x2)+C\cos(x^2) + C

u=x2du=2xdxu = x^2 \Rightarrow du = 2x \, dx. So cosudu=sinu+C=sin(x2)+C\int \cos u \, du = \sin u + C = \sin(x^2) + C.

Problem #0125 International

Problem 9Antiderivatives

cosxdx\displaystyle\int \cos x \, dx equals:

Show answer & worked solution
  1. A. cosx+C-\cos x + C
  2. B. sinx+C-\sin x + C
  3. C. sinx+C\sin x + C✓ correct
  4. D. tanx+C\tan x + C

cosxdx=sinx+C\int \cos x \, dx = \sin x + C.

Problem #0014 International

Problem 10Integration by Parts

Compute 01xexdx\displaystyle\int_0^1 x e^x\, dx.

Show answer & worked solution
  1. A. 00
  2. B. 11✓ correct
  3. C. e1e - 1
  4. D. e+1e + 1

xexdx=xexexdx=(x1)ex+C\int x e^x\,dx = x e^x - \int e^x\,dx = (x-1)e^x + C. Evaluating from 00 to 11: (0)e(1)1=0(1)=1(0)\cdot e - (-1)\cdot 1 = 0 - (-1) = 1.

Which exam are you sitting?