Question

Найдите sin а, если cos а = -0,8, 180° < a < 270°

Answer 1

Ответ ниже... да да да

Answer 2

sinα=-√(1-cos²α)=-√(1-0/64)=-√0.36=-0.6 c учетом третьей четверти.

Answer 3

To find the value of sin(a), we can use the identity sin^2(a) + cos^2(a) = 1.

Given cos(a) = -0.8, we can square both sides of the equation to find sin^2(a):

sin^2(a) + (-0.8)^2 = 1

sin^2(a) + 0.64 = 1

sin^2(a) = 1 - 0.64

sin^2(a) = 0.36

Taking the square root of both sides, we get:

sin(a) = ±√0.36

Since the angle a is in the third quadrant (180° < a < 270°), the value of sin(a) will be negative.

Therefore, sin(a) = -0.6.