$\frac{dy}{dx}=\frac{-2xy}{1-x^2},y\left(0\right)=2$

$12+27:3-3+11$

$x-6=2$

$\frac{2x}{2}+x>-1$

$6+\left(-4\right)\cdot\left(3^2\cdot0\right)-6\cdot0.5$

$\lim_{x\to0}\left(\frac{sin2x}{2x^2+x}\right)$

$\frac{\sec\left(x\right)}{\cos\left(x\right)}=\frac{1}{\cos^2\left(x\right)}$