$49a^2+56ab+16b^2$

$\lim_{x\to0}\left(-\frac{\sin\left(x\right)}{\cos\left(x\right)}\right)$

$\cos2\left(x\right)\cos\left(x\right)-\sin2\left(x\right)\sin\left(x\right)=-\frac{\sqrt{3}}{2}$

$x^2-2\le0$

$\left(2ab^2+5x^2y^{-3}\right)^2$

$\int16x^{-3}dx$

$\lim_{x\to\infty}\left(\frac{x-y}{x+y}\right)$