Question

sin
$sin {}^{2} 40 + \sin {}^{2}50$
​

Answer 1

Answer:

sin^2(40)+sin^2(50)

sin^2(40)+sin^2(90-40)

sin^2(40)+cos^2(40)

1 (sin^2 theta+cos^2 theta=1)

Answer is 1

Hope it helps..........

Answer 2

Answer:

$\sin {}^{2} 40 {}^{} +sin {}^{2}50 \\ \sin {}^{2} 40 + \cos{}^{2} (90 - 50) \\ \sin {}^{2} 40 + \cos{}^{2} 40 \\ 1$

using identity,

sin²Φ + cos²Φ = 1