$4a^2-5a+3$

$sin\left(4x\right)=-8cos^3xsin\left(-x\right)-4cos\left(-x\right)sinx$

$x+2-14-x$

$\cot\left(a\right)^2+\frac{\sin\left(a\right)^2}{1+\cos\left(a\right)^2}=\csc\left(a\right)^2$

$\int y.sen\left(y\right)dy$

$\left(9-6x^3\right)\left(6x^3+9\right)\left(81+36x^4\right)$

$25x^4-49y^6$