$x^2-20x-525=0$

$\left(\frac{2z^6}{6z^3}\right)^2$

$\lim_{p\to-1}\left(\frac{b^{p+1}}{p+1}\right)ln\left(ab\right)$

$\sqrt{\frac{\sec\left(x\right)-\cos\left(x\right)}{\sec\left(x\right)}}$

$-\frac{1}{tan}$

$\left(1+\frac{\sin\left(x\right)}{\cos\left(x\right)}\right).\frac{\cos\left(x\right)}{\sin\left(x\right)}$

$\frac{\sqrt{x}}{2}+\frac{x^{-\frac{1}{2}}}{2}$