$\frac{dx}{dy}=x\cos\left(y\right)$

$\int\cos\left(4\right)\cdot\sin\cdot dx$

$25x^2-10x+4$

$\left(7x^6+4x^4\right)\cdot\left(7x^6-4x^4\right)$

$\int_e^{\infty}\left(\frac{x+1}{e^{2x}}\right)dx$

$\lim_{u\to0}\left(\frac{\left(u+1\right)^{1+u}-u-1}{\ln\left(1+u\right)-u}\right)$

$x^2+2x+3x$