$\frac{d^{11}}{dx^{11}}\left(sin^2\left(x\right)\right)$

$\int36t^8e^{-t^9}dt$

$\frac{d}{dx}8x^2y$

$3+12\cdot19-10$

$\frac{cos\left(a\right)cos\left(b\right)+sin\left(a\right)sin\left(b\right)}{cos\left(a\right)cos\left(b\right)}$

$3ab-5abc+8ab+6abc-10+14ab-20$

$x\:.\:\left(-9\right)=-81$