[tex] \int \frac{dx}{x} = log(x) + c \\ \int \frac{f \prime(x)}{f(x)} = log \mid \: f(x) \mid + c \\ \int \: tan(x)dx = \int \: \frac{sin(x)}{cos(x)} dx \\ = - log|cos(x)| + c \\ = log |sec(x)| + c \\ the \: same \: rule \: goes \: for \: cot...etc.\\\int {sec}^{2}(x)dx=|tan(x)|+c\\let u=tanx\\ \frac{du}{dx}={sec}^{2}(x)\rightarrow {du}={sec}^{2}(x)dx\\ \int du=|u|+c\\ \therefore tan|x|+c[/tex]
Step-by-step explanation:
Am not sure what your question is? But if you are asking about a proof, then you may use Taylor series to prove these integrals...