$\lim_{x\to1}\left(\frac{sin\left(\pi x\right)}{cos\left(\pi x\right)+x}\right)$

$\int\frac{\left(9e^x+6e^{-x}\right)}{\left(9e^x-6e^{-x}\right)}dx$

$\frac{dy}{dx}=\frac{x^2e^x}{ysin\left(y^2+1\right)}$

$7x^2+4y^2-7^2+6^2$

$\frac{1-cos2x}{cos^2x}=\frac{2}{cot^2x}$

$\left(x-11\right)^2=0$

$\lim_{x\to\infty}\left(\frac{\left(7x^2-4\right)}{x}\right)$