Question

How do you use `tantheta=4` to find `sectheta`?

Answer 1

Use the identity `sec(theta) = +-sqrt(1 + tan^2(theta))`

Explanation:

Given: `tan(theta) = 4`

Substitute `(4)^2` for `tan^2(theta)` into the identity:

`sec(theta) = +-sqrt(1 + 4^2`

`sec(theta) = +-sqrt17`

Whether the secant is positive or negative cannot be determined with the given information.