$$\int\frac{\cos2\left(x\right)}{\left(\cos\left(x\right)\right)\left(\sin\:\left(x\right)\right)}dx$$

$$\left(x-10\right)\left(x+15\right)$$

$$\frac{d^2}{dx^2}\:4\cos^2x$$

$$\:2^2-234+4^2$$

$$-11-\left(-72\right)$$

$$m^2+3m-27$$

$$\frac{d}{dx}e^9$$