Question

If sin A + sin^2A =1, then find the value of the expression (cos^2 A+ cos^4 A).​

Answer 1

The answer is in attached photo.

Answer 2

Answer Crack:

Tip: These types of sums don't follow a general pattern. But a question based approach to solve.

So,

Sin A + Sin^2 A = 1

Sin A = 1 - Sin^2 A

Sin A = Cos^2 A (Trigo property #1)

Squaring both sides;

Sin^2 A = Sin^4 A

1 - Cos^A = Sin^4 A

Cos^2 A + Cos^4 = 1