$x+x^{-1}=4$

$\lim_{x\to\infty}\left(\frac{\sin\left(\frac{1}{x}\right)}{\arctan\left(\frac{1}{x}\right)}\right)$

$( x ^ { 2 } + y ^ { 2 } ) ^ { 5 }$

$\int e^x\cos\left(c\right)dx$

$\int\left(2-x\right)\cdot e^{4-x}$

$7\cdot\left(-3\right)\cdot9+9$

$\frac{dy}{dx}=6x^2\left(2+y\right)$