Integrals: functions and by parts

Integrals of exponential functions

The integral of exe^x is ex+Ce^x+C, and the integral of axa^x is axlna+C\frac{a^x}{\ln a}+C.

exdx=ex+C,axdx=axloga+C\begin{gathered} \int e^x\,dx=e^x+C, \\[4pt] \int a^x\,dx=\frac{a^x}{\log a}+C \end{gathered}

exe^x stays exe^x whether you differentiate or integrate. For base aa, differentiation multiplies by lna\ln a, so integration divides by it.

axdx=axlna+C\int a^x\,dx=\frac{a^x}{\ln a}+C

When the exponent is linear, as in e2xe^{2x}, remember to divide by the coefficient of xx.

Examples

  1. 01What is the value?01exdx\displaystyle \int_{0}^{1} e^{x}\,dxAnswerHide
    Answere1\displaystyle e-1
  2. 02Integrateexdx\displaystyle \int e^x \, dxAnswerHide
    Answerex+C\displaystyle e^x + C
  3. 03What goes in □?axdx=ax\displaystyle \int a^{x}\,dx = \frac{a^{x}}{\square}AnswerHide
    Answerlogea\displaystyle \log_e a
  4. 04What is this?exdx\displaystyle \int e^{x}\,dxAnswerHide
    Answerex+C\displaystyle e^{x}+C
  5. 05What is this?3xdx\displaystyle \int 3^{x}\,dxAnswerHide
    Answer3xloge3+C\displaystyle \frac{3^{x}}{\log_e 3}+C
  6. 06What is this?5xdx\displaystyle \int 5^{x}\,dxAnswerHide
    Answer5xloge5+C\displaystyle \frac{5^{x}}{\log_e 5}+C

FAQ

Q1What is e2xdx\int e^{2x}\,dx?Show answerHide
A
12e2x+C\frac{1}{2}e^{2x}+C. Differentiation multiplies by the inside coefficient 2, so integration divides by 2.

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Published 2026-09-03 · Updated 2026-09-05