$\int\frac{e^{x}-1}{e^{x}+1}dx$

$y'+y\cdot tan\left(t\right)=cos\left(t\right)$

$\lim_{x\to0}\left(\frac{sin9x}{x}\right)$

$\frac{\sin\left(x\right)}{1-\cos\left(x\right)}-\frac{\sin\left(x\right)}{1-\cos\left(x\right)}$

$\int\left(\frac{x}{\left(9+25x^2\right)^3}\right)dx$

$-\cos^3\left(x\right)+2\cos\left(x\right)$

$\int3x^2\sec^2\left(4x^3-5\right)dx$