$\left(3x^2y+8xy^2\right)dx+\left(x^3+8x^2y+12y^2\right)dy=0$

$\lim_{x\to\infty}\left(\frac{1-\sin\:^2\left(x\right)-\cos\:^2\left(x\right)}{x}\right)^{\frac{1}{x}}$

$\left(x^3-0.3\right)^2$

$\sin\left(x\right)\sin\left(2x\right)-\cos\left(x\right)\cos\left(2x\right)$

$3^{-4}\cdot3^{-1}\cdot3^6$

$\frac{\left(2sin\left(x-y\right)\right)}{cos\left(x+y\right)-cos\left(x-y\right)}$

$sin2x\:-\:2cosx^2\:=\:0$