Trig calculus

The derivations for these identities are quite insane, and must be studied at a later date, when sanity is abundant and assignments are few.

Differentiation

sinxcosx\sin{x}\Rightarrow\cos{x} cosxsinx\cos{x}\Rightarrow-\sin{x} tanxsec2x\tan{x}\Rightarrow\sec^{2}{x} secxsecxtanx\sec{x}\Rightarrow\sec{x}\tan{x} cscxcscxcotx\csc{x}\Rightarrow-\csc{x}\cot{x} cotxcsc2x\cot{x}\Rightarrow-\csc^{2}{x} arctanx11+x2\arctan{x}\Rightarrow\frac{1}{1+x^{2}}

arcsinx11x2\arcsin{x}\Rightarrow\frac{1}{\sqrt{1-x^{2}}} arccosx11x2\arccos{x}\Rightarrow-\frac{1}{1-x^{2}} sinhxcoshx\sinh{x}\Rightarrow\cosh{x} coshxsinhx\cosh{x}\Rightarrow\sinh{x} tanhxsech2x\tanh{x}\Rightarrow\sech^{2}{x} arcsinhx11+x2\arcsinh{x}\Rightarrow\frac{1}{\sqrt{1+x^{2}}} arccoshx1x21\arccosh{x}\Rightarrow\frac{1}{\sqrt{x^{2}-1}} arctanhx11x2\arctanh{x}\Rightarrow\frac{1}{1-x^{2}}

Integration

1x2+a2=1aarctanx\int{\frac{1}{x^{2}+a^{2}}}=\frac{1}{a}\arctan{x}