$\lim_{x\to1}\left(\sen\left(\frac{\pi}{x^{2}-1}\right)\right)$

$\left(x^2+1\right)\frac{dy}{dx}+3x^3y=6xe^{-\frac{3}{2}x^2}$

$\left(xy^4-5\right)^2$

$\frac{\tan\left(-x\right)+\cot\left(x\right)}{\tan\left(x\right)}=-\csc^2\left(x\right)$

$7x^2-9x+2=0$

$12-1600$

$\frac{\sin\:\left(x+h\right)-\sin\:\left(x\right)}{h}=\frac{2\sin\:\left(\frac{h}{2}\right)\cdot\:\cos\:\left(x+\frac{h}{2}\right)}{h}$