Question

Prove that...sin^4α+sin^2αcos^2α=sin^2α​

Answer 1

Note that LHS means left-hand side and RHS means right-hand side.

Explanation:

LHS = sin⁴a + sin²a cos²a

= sin²a (sin²a + cos²a)

At this point, you can use the identity sin²a + cos²a = 1,

= sin²a (1)

= sin²a

= RHS (Proved)

Answer 2

Explanation:

`\Large \boldsymbol{} \sin^4a+\sin^2a \cos^2a=\sin^2a \\\\\sin^2a(\underbrace{\sin^2a+\cos^2a}_1) =\sin^2a \\\\\sin^2a\cdot 1=\sin^2a \\\\\sin^2a=\sin^2a`