$1-\frac{\cos^{2}\theta}{1+\sen\theta}=\sen\theta$

$\left[-2\left(-2\right)\right]:\left[2\left(-2\right)\right]4$

$\frac{3}{5}x^2y+0,35x+\frac{11}{121}x+0,47x^2y+1\frac{3}{5}x^2y$

$\frac{dy}{dx}=\frac{6x-12}{x^2}\:;\:y\left(1\right)=20$

$9cosx-12sin^2xcosx=0$

$\int ln\left(x-6\right)dr$

$\int\left(-\frac{1}{\sqrt{4-x^2}}\right)dx$