##
If sin A + sin
^{
2
}
A = 1, then the value of the expression (cos
^{
2
}
A + cos
^{
4
}
A) is

## (A) 1 (B) 1/2 (C) 2 (D) 3

Last updated at Aug. 19, 2021 by Teachoo

Transcript

Question 12 If sin A + sin2 A = 1, then the value of the expression (cos2 A + cos4 A) is (A) 1 (B) 1/2 (C) 2 (D) 3 Given sin A + sin2 A = 1 sin A = 1 − sin2 A sin A = cos2 A Now, cos2 A + cos4 A = cos2 A + (cos2 A) 2 Putting cos2 A = sin A = sin A + sin2 A Given sin A + sin2 A = 1 = 1 So, the correct answer is (A)

NCERT Exemplar - MCQ

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.