Q12. If cos A + cos2 A = 1, then sin2 A + sin4 A is equal to
Question
(a) -1
(b) 0
(c) 1
(d) None of these
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Class 10 Maths
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2021-12-23T10:55:22+00:00
2021-12-23T10:55:22+00:00 1 Answer
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Answer ( 1 )
Answer: (c) 1
cosA+cos2A=1
cosA=1−cos2A
cosA=sin2A
Hence
sin4A+sin2A
cos2A+cosA
=1