Question

If sin a + sin2a=1, then cos2a+ cos4a=?

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Answer 1

Answer:

0

Step-by-step explanation:

cos2a=1-2(sina)^2

cos4a=1-2(sin2a)^2

=2-2(sina+sin2a)^2

=2-2

=0

Answer 2

Answer:

if sin a +sin wet a=1,then cos2a+cos4a=

first sin 2a value is =1 then cos2a is =1 and cos4a value is 2 because 2 value is one and 2 +2, =4 =1+1,=3

the answer is cos3a