$$\frac{d}{dx}\left(y=x^2cos2^x\right)$$

$$\left(-2a\:+\:3b\right)^2$$

$$\left(-5y+8\right)^4$$

$$1+128^4$$

$$\sin\left(x\right)\sin\left(2x\right)-\cos\left(x\right)\cos\left(2x\right)$$

$$\lim_{x\to-4}\left(\frac{2x^2-32}{x+4}\right)$$

$$100-y^6$$