$$\frac{1}{sec^2x}=1-\frac{1}{csc^2x}$$

$$x^2+4x+7$$

$$-10+x-3y+4x-9x+y-2$$

$$\frac{dy}{dx}=\frac{x^2y+x^2+y+1}{xy+x}$$

$$36x^2-6x-90$$

$$\lim_{x\to\infty}\left(\left(\sqrt{x}\left(\sqrt{x+1}-\sqrt{x-1}\right)\right)\right)$$

$$\int\frac{1}{x\sqrt{4x-2}}dx$$