$2^3+\left(8-5\right)\cdot4-5^2$

$\tan\left(a\right)+\cot\left(a\right)=\frac{\sec^2\left(a\right)+\csc^2\left(a\right)}{\sec\left(a\right)\csc\left(a\right)}$

$21\:+\:8w\:=\:85$

$\frac{\left(tan^2x-sec^2x\right)}{cosx}$

$1000-b^3$

$\lim_{x\to-5}3x^2-4x^2+2x-1$

$-\sqrt{63}$