$\lim_{x\to4}x^2+5$

$\lim_{t\to0}\left(\frac{2\sin\left(5t^8\right)}{-3t}\right)$

$\left\{4a+2b\right\}+\left\{3a+b\right\}$

$\frac{2\:tan\:x}{1\:+tan\:x}=sen^2x$

$\lim_{x\to\infty}\left(\sqrt[f]{f}\right)$

$\frac{\sin\left(x\right)}{1-\cos^2\left(x\right)}$

$\lim_{x\to0}\left(\frac{-4\sin\left(9x^3\right)}{3x}\right)$