$9x-4<0$

$\lim_{x\to\infty}\left(\frac{ln\left(x^6-3\right)}{ln\left(x\right)cos\left(\frac{1}{x}\right)}\right)$

$-\sin\left(x\right)+x\cos\left(x\right)+\ln\left(\sec\left(x\right)\sin\left(x\right)\right)$

$\lim_{x\to0}\left(\frac{x^2+7x+6}{x^2-1}\right)$

$\:4x^2-\left(3x-5\right)^2$

$4a^2-4a-3$

$1+\sqrt{3}+1-\sqrt{3}$