$$\frac{cos\left(a+b\right)}{sin\left(a-b\right)+cos\left(a\right)sin\left(b\right)}$$

$$5x\left(x^4\right)^2$$

$$\left(1-x+4a\right)\left(1-x+3a\right)$$

$$\int5y^23^{2y}dx$$

$$37\sin\left(x-101\right)$$

$$.\int_1^2\left(xe^{-2x}\right)dx$$

$$\lim_{x\to3}\left(\frac{4x^2-36}{x-3}\right)$$