$$2n^2-8n^2$$

$$\int tan^{-3}\left(x\right)sec^2xdx$$

$$\left(2x\right)\left(y+3\right)\left(z-1\right)$$

$$\left(\frac{dy}{dx}\right)-\frac{y}{x}=1-\frac{1}{x}$$

$$-13+9\left|\left(-3\right)+9\right|$$

$$-9-\left(-40\right)$$

$$\cot^3\left(x\right)=\cot\left(x\right)\left(\csc^2\left(x\right)-1\right)$$