Question

2 sin²15+2 sin²75 is equal to.

Answer 1

2 sin² 15 + 2 sin²75 = 2( sin²15 + sin²75)

sin²75 = cos²15 { sin(90-Ф) = cosФ )

2(sin²15 + sin²75 )

= 2( sin²15 + cos²15 )

= 2 {sin²Ф + cos²Ф = 1}

Hope this helps