$\lim_{x\to0}\left(\frac{sin^2\left(x\right)}{ln\left(1+3x\right)}\right)$

$-3\cdot6+4\cdot3+2$

$\frac{d^2}{dx^2}\left(x\cdot\cos\left(x\right)\right)\sqrt{3-x^2}$

$2a=6$

$5x^2-0x-4$

$\int x\cdot\cos\left(1+x\right)dx$

$4000\int_9^{\infty}\left(e^{-x}\cos\left(x\right)\right)dx$