Mathematics
Answer
Given,
sin A + sin2 A = 1
It can be written as
sin A = 1 - sin2 A …. (1)
We have to find the value of (cos2 A + cos4 A)
Using the trigonometric identities,
cos2 A = 1 - sin2 A ….. (2)
From both the equations
sin A = cos2 A
Now, (cos2 A + cos4 A) = (cos2 A + (sin A)2)
= cos2 A + sin2A
cos2 A + sin2 A = 1
Therefore, (cos2 A + cos4 A) = 1
Hence, option 2 is the correct option.