$\lim_{x\to\infty}\frac{x^2}{\sqrt{x^2+1}}$

$\int\:\frac{cos^2x}{1-sinx}dx$

$\frac{\sin\:^{\left(2\right)}\left(x\right)-\sin\:\:\left(x\right)}{\cos\:\left(x\right)-\sin\:\left(x\right)\cos\:\left(x\right)}$

$7=x^2-2$

$\left(2x+3yc\right)^2$

$\tan^2\left(x\right)=\sec\left(x\right)\csc\left(x\right)\tan\left(x\right)-1$

$16x^6-16x^3-4$