$\lim_{x\to\infty}\left(\frac{x+\sin\left(x\right)}{3x+\cos\left(x\right)}\right)$

$4x^2-2xy+y^2=\left(x+y\right)^2$

$2x^3+4$

$\left(\cot\left(x\right)-\csc\left(x\right)\right)\left(\cos\left(x\right)x+\right)$

$3.7+-1.6$

$4\sec^2-3\:=\:1\:+\:4\tan^2$

$\lim_{x\to0}\left(\frac{1}{x}-\frac{1}{sinhx}\right)$