$\frac{\left(2sin\left(\frac{8x}{2}\right)cos\left(\frac{4x}{2}\right)\right)}{\left(-2sin\left(\frac{8x}{2}\right)sin\left(\frac{4x}{2}\right)\right)}$

$68xy^2-34x^2+51$

$4\left(3+v\right)-v=6+3\left(v+2\right)$

$\left(1+\tan\left(a\right)\right)\sec^2\left(a\right)=1$

$\sqrt{\frac{x-7}{\sqrt{\sqrt{x}}}}$

$\left(-2-h\right)^2$

$\lim_{x\to y}\left(\frac{\sin\left(x\right)-\sin\left(y\right)}{x-y}\right)$