$$\lim_{x\to0}\left(\frac{1}{x\cdot\:sin\left(x\right)}-\frac{1}{x\cdot\:tan\left(x\right)}\right)$$

$$\frac{dy}{dx}4x^3e^{x^2+3x+2}$$

$$\int\frac{x^2+3x+1}{x-1}dx$$

$$18bc^2-24^2c$$

$$\frac{2sin\left(2x\right)-sin\left(4x\right)}{2sin\left(2x\right)+sin\left(4x\right)}=\tan\left(x\right)^2$$

$$\left(5f^2+2r\right)^2$$

$$\lim_{x\to-1}\left(\frac{sin\left(x^3+1\right)}{x^5+1}\right)$$