wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Question 9
If
sinA+sin2A=1, then the value of (cos2A+cos4A) is

(A) 1
(B) 12
(C) 2
(D) 3

Open in App
Solution

The answer is (A).

Given, sinA+sin2A=1

sinA=1sin2A=cos2A [sinθ+cos2θ=1]

On squaring both sides we get,

sin2A=cos4A

1cos2A=cos4A

cos2A+cos4A=1(Ans.).

flag
Suggest Corrections
thumbs-up
194
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon