$\lim_{x\to\infty}\left(\frac{x^2+x}{x^2+1}\right)$

$sin2x-3sinx$

$\int\frac{\left(x-1\right)\left(x+1\right)}{\left(2x^3-6x+5\right)}dx$

$\lim\:_{x\to\:\infty\:}\left(1+\frac{6}{x}+\frac{4}{x^2}\right)^x$

$sec^2x-1=\frac{sin^2x}{cos^2x}$

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

$5.50-1.70$