Question

plz solve this guys!!! I want a detailed explanation.​

Answer 1

Answer:

Step-by-step explanation:

Here's is the solution

Answer 2

Hey there!

L.H.S:

( cos α + cos β) ² + ( sinα + sin β)²

= cos² α + cos²β + 2 * cosα * cosβ + sin²α + sin²β + 2 * sin α * sinβ

= (cos²α + sin²α) + (cos²β + sin²β) + 2 ( cosα * cosβ + sinα*sinβ)

= 1  + 1  + 2 cos(α - β)

= 2 + 2 cos(α-β)

= 2 [ 1 + cos(α - β)

= 2 * 2 cos²(α - β) / 2        { ∵ 1 + cosФ = 2cos²(Ф/2) }

= 4 cos²(a-β)/2

= R.H.S

Hence, proved!