$$\int\:x\:sen\:\left(5x\right)\:dx$$

$$y''+6y'+9y=0$$

$$\left(\frac{x}{2}\right)-\left(\frac{2}{3}\right)^3$$

$$csc\frac{1}{4}x-2=0$$

$$\int\frac{x^5+x^3-x}{x^2}dx$$

$$\int cos\left(4x-\frac{\pi}{4}\right)dx$$

$$\sin^2\left(a\right)\cos^2\left(a\right)+\sin^4\left(a\right)$$