$\left(-9\right)\::\:1\:$

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

$\int\:\left(5cos\:x+4sen\:x\right)dx$

$4\frac{dy}{dx}-2x^2y=0$

$\int\frac{12x^2}{1+sin\left(x^3\right)}dx$

$\frac{3m}{11}\left(\frac{11m}{7}+\frac{7n}{11}\right)-\frac{11n}{3}\left(3+\frac{3m}{11}\right)$

$\sin^2+.36=1$