Question

How do you simplify `f(theta)=cot2theta-2cos2theta+sec2theta` to trigonometric functions of a unit `theta`?

Answer 1

`f(theta)=cot2theta-2cos2theta+sec2theta`

`=(1-tan^2theta)/(2tantheta)-(2(1-tan^2theta))/(1+tan^2theta)+(1+tan^2theta)/(1-tan^2theta)`