$2cos^2\left(x\right)+3cos\left(x\right)+1$

$\frac{dy}{dx}=\left(\frac{\left(xy+2x-y-2\right)}{\left(xy+3x+3y+9\right)}\right)$

$\frac{x^5-x^4+x^2-2}{x^2+1}6$

$55,13-44,50$

$9y^6+11y^3+25x;\:x=1;\:y=-1$

$\frac{6y^8}{2y^5}$

$\left(a+4\right)\left(a-4\right)\left(a^2+16\right)$