Solve the Equation Given Below
If sinθ+sin2θ=1, then the value of cos2θ +cos4θ is:
- 2
- 0
- 1
- -1
Answer: (3) 1
Explanation:-
sinq + sin2q = 1 …………………… (1)
sinq = 1 – sin2q
sinq = cos2q
Now, cos2q + cos4q
Put, cos2q = sinq
Then, sinq + sin2q = from equation (1) .
Hence, the answer is (3) 1.