Question

Solve the given equation
2sin²ø-cosø=1
using identities

Answer 1

2sin²ø-cosø=1
2(1-cos²ø)-cosø=1
2 - 2cos²ø -cosø -1 = 0
1 - 2cos²ø -cosø = 0
2cos²ø + cosø - 1 = 0
(2cosø-1)(cosø+1) = 0
for zeros, take
2cosø-1=0 --->cosø=1/2 ---> ø=....?
cosø+1=0 ---> cosø = -1 ---> ø=....?

Answer 2

thank you!

Answer 3

welcome