Question

How do you solve the equation `3costheta-1=4` for `0<=theta<2pi`?

Answer 1

No solutions are possible for this equation.

Explanation:

The maximum value of `cos(theta)` for any value of `theta` is `1`

Therefore the maximum value of `3cos(theta)` is `3`
and
the maximum value of `3cos(theta)-1` is `2`

Therefore `3cos(theta)-1` can not be equal to `4` for any value of `theta`