Question

Cos 2L, якщо sin L =3/5,0<2<π/2.

Answer 1

Ответ: 24/25

Объяснение:

0 < L < π/2 ⇒ cosL > 0

cos² L = 1 - sin² L = 1 - (3/5)² = 1 - 9/25 = 16/25

cos L = √(cos² L) = √(16/25) = 4/5

cos 2L = 2sin L * cos L = 2 * (3/5) * (4/5) = 24/25