Toolkit 102

Basic Integrals

Definition (Signed Area)

Signed area represented by a definite integral
abf(x)dx\int_a^b f(x)\,dx

The definite integral represents the signed area between the graph of f(x) and the x-axis.


Basic Properties

aaf(x)dx=0\int_a^a f(x)\,dx=0
abf(x)dx=baf(x)dx\int_a^b f(x)\,dx=-\int_b^a f(x)\,dx
acf(x)dx=abf(x)dx+bcf(x)dx\int_a^c f(x)\,dx=\int_a^b f(x)\,dx+\int_b^c f(x)\,dx
ab(f(x)±g(x))dx=abf(x)dx±abg(x)dx\int_a^b(f(x)\pm g(x))\,dx=\int_a^b f(x)\,dx\pm\int_a^b g(x)\,dx
abcf(x)dx=cabf(x)dx\int_a^b c f(x)\,dx=c\int_a^b f(x)\,dx

Common Antiderivatives

xndx=xn+1n+1+C(n1)\int x^n\,dx=\frac{x^{n+1}}{n+1}+C\qquad(n\ne-1)
1xdx=lnx+C\int\frac1x\,dx=\ln|x|+C
exdx=ex+C\int e^x\,dx=e^x+C
axdx=axlna+C(a>0,a1)\int a^x\,dx=\frac{a^x}{\ln a}+C\qquad(a>0,a\ne1)
sinxdx=cosx+C\int\sin x\,dx=-\cos x+C
cosxdx=sinx+C\int\cos x\,dx=\sin x+C
tanxdx=lncosx+C\int\tan x\,dx=-\ln|\cos x|+C
cotxdx=lnsinx+C\int\cot x\,dx=\ln|\sin x|+C