Question

Given `sectheta=5` and `tantheta=2sqrt6`, how do you find `costheta`?

Answer 1

`1/5`

Explanation:

Use trig identity:
1/(cos^2 a) = sec^2 a
`cos^2 t = 1/(sec^2 t) = 1/ 25`
`cos t = 1/5`