$cos^2\left(2x\right)-sen^2\left(2x\right)=1$

$x<3x-1$

$\frac{d}{dx}\left(e^y+ax^2-5y-6=0\right)$

$2xsin^2ydx-\left(x^2+10\right)cosydy=0$

$\int_1^2\left(\frac{\sqrt{9-x^2}}{x^4}\right)dx$

$\frac{1}{9}-\frac{49}{16}b\left(12\right)$