$sin\left(2x\right)-2sin\left(x\right)+1=0$

$\lim_{x\to0}\left(\frac{e^{14x}-1-14x}{x^2}\right)$

$36x^2+36x+5$

$\left(-3mn+r\right)\left(r+3mn\right)$

$\frac{2x^2+0x-4}{x-2}$

$\int\frac{cotx}{ln\left(sinx\right)}dx$

$\lim_{x\to+\infty\:\:}\left(-in\left(x+1\right)-in\left(x\right)\right)$