$\sin\left(x\right)^2+\frac{1}{\sec\left(x\right)^2}=1$

$\lim_{t\to0}\frac{e^t+e^{-t}}{t^2}$

$\int\frac{x^2+x+6}{x^2+4}dx$

$4-3\cdot2+6\left(-2\right)-1$

$\cos^2\left(x\right)-\sin\left(x\right)=\sin^2\left(x\right)$

$\frac{\left(y^2\right)^2}{x^4y^3}$