# Integration Basics ## Standard Integrals - $\int x^n \, dx = \frac{x^{n+1}}{n+1} + C$ for $n \neq -1$ - $\int \frac{1}{x} \, dx = \ln|x| + C$ - $\int e^x \, dx = e^x + C$ - $\int a^x \, dx = \frac{a^x}{\ln a} + C$ - $\int \sin x \, dx = -\cos x + C$ - $\int \cos x \, dx = \sin x + C$ - $\int \sec^2 x \, dx = \tan x + C$ - $\int \csc^2 x \, dx = -\cot x + C$ - $\int \frac{1}{\sqrt{1-x^2}} \, dx = \sin^{-1} x + C$ - $\int \frac{1}{1+x^2} \, dx = \tan^{-1} x + C$ ## Integration by Substitution $\int f(g(x)) g'(x) \, dx = \int f(u) \, du$ where $u = g(x)$ ## Integration by Parts $\int u \, dv = uv - \int v \, du$ LIATE priority for choosing $u$: Logarithmic, Inverse trig, Algebraic, Trigonometric, Exponential ## Partial Fractions $\frac{P(x)}{(x-a)(x-b)} = \frac{A}{x-a} + \frac{B}{x-b}$ $\frac{P(x)}{(x-a)^2} = \frac{A}{x-a} + \frac{B}{(x-a)^2}$ ## Definite Integrals Properties - $\int_a^b f(x) \, dx = -\int_b^a f(x) \, dx$ - $\int_a^b f(x) \, dx = \int_a^c f(x) \, dx + \int_c^b f(x) \, dx$ - $\int_0^a f(x) \, dx = \int_0^a f(a-x) \, dx$ - If $f$ is even: $\int_{-a}^a f(x) \, dx = 2\int_0^a f(x) \, dx$ - If $f$ is odd: $\int_{-a}^a f(x) \, dx = 0$