$\frac{1}{cos^2x}+\frac{sen^2x}{cos^2x}$

$10abc-20ab+50ad-60abd$

$cos\:x=3\:cos\:x\:\left(1+sin\:x\right)$

$\int-6x\sin\left(3x^2+8\right)dx$

$\frac{\cos\left(5g\right)}{\sin\left(g\right)}-\frac{\sin\left(5g\right)}{\cos\left(g\right)}=\frac{\cos\left(6g\right)}{\sin\left(g\right)\cdot\cos\left(g\right)}$

$3b-14=6b-26$

$2\tan\left(x\right)\cos^2\left(x\right)-1=0$