Question

$sin^{2} 150 + sin^{2} 60 = 1$

Answer 1

sin 150 = sin (180-150) = sin 30
sin 60 = cos(90-60)= cos 30 si adunandu-le, obtinem
-------------------------------------------------
sin^2 30° + cos^2 30° = 1
----------------------------------------

Answer 2

$\it sin 150^ o = sin 30^o = \dfrac{1}{2}\\\;\\sin60^ o = \dfrac{\sqrt3}{2}$

$\it sin^2 150^o +sin^2 60^o = \left(\dfrac{1}{2}\right)^2+\left(\dfrac{\sqrt3}{2}\right)^2 = \dfrac{1}{4} + \dfrac{3}{4} = 1$