$\frac{1-\sen^{2}\theta}{\sec^{2}\theta}=\cos^{4}\theta$

$x^2-4x+-4$

$sin\left(arccos\left(\frac{3}{4}\right)-arctan\left(\frac{1}{2}\right)\right)$

$-2\sin\left(x\right)+\sqrt{2}=0$

$5\sin\left(x\right)+2=\sin\left(x\right)$

$2\cdot e^x\cdot\frac{dy}{dx}=\frac{x}{y^3}$

$\frac{\left(sin\left(4t\right)-sin\left(2t\right)\right)}{\left(cos\left(4t\right)+cos\left(2t\right)\right)}$