Question

Find all solutions of the given equation. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to two decimal places where appropriate.)
sec2 θ − 4 = 0

Answer 1

\[\sec^2\theta - 4 = 0\]

Answer 2

1° Rearrange: sec2(theta)=4
2° Rearrange further: sec(theta)=±2
3° Use the trig identity sec=1/cos: 1/cos(theta)=±2
4°Rearrange to make cos(theta)=1/±2
I should hope you can work it out from here! (you should get two solutions)