Question

Prove that :
sin229° + sin261°=1

Answer 1

Step-by-step explanation:

{sin (90 - 61)}² + sin²61 = ( cos61)² + sin²61 = cos²61 + sin²61 = 1, since sin²θ + cos²θ = 1

Answer 2

Correct Question

Prove that sin²(29°) + sin²(61°) = 1

Proof

We know that

sin∅ = cos(90° - ∅)

⇒ sin(61°) = cos(90° - 61°)

⇒ sin(61°) = cos(29°)

Now, squaring both sides, we get

sin²(61°) = cos²(29°)

Now, sin²(29°) + sin²(61°)

Put sin²(61°) = cos²(29°)

⇒ sin²(29°) + cos²(29°)

Now, we know that sin²∅ + cos²∅ = 1

hence, sin²(29°) + cos²(29°) = 1

Hence Proved.