Question

If cos theta + cos² theta = 1, then cos theta is equal to
(a) 2 Sin 18 degrees
(b) 2 Cos 72 degrees
(c) Sin 18 degrees
(d) 2 Sin 162 degrees

pls solve this question with full explanations
best answer i will mark brainliest 100%​

Answer 1

Answer:

hmm ok I got 2 cos 72 degrees please follow me and mark my answer