$$\frac{d}{dx}\left(\sqrt{x-y}\right)$$

$$70x^2+12x+16$$

$$f\left(x\right)=\left(x^2+2x-8\right)\cdot\left(x+1\right)$$

$$1203+101$$

$$x^2+x-1>0$$

$$\cos^2\left(x\right)\left(1-\tan^2\left(x\right)\right)=\cos^2\left(x\right)$$