Question

Известно что sinα=-0,6, π<α<3π/2, найдите значение cos α.

Answer 1

Альфа в 3ем ч.
А там соs отрицательный. Соs a= 1- (-0.6×(-0.6))= -0.8

Answer 2

To find the value of cos α, we can use the trigonometric identity:

sin^2 α + cos^2 α = 1

Given that sin α = -0.6, we can square this value to get sin^2 α:

sin^2 α = (-0.6)^2 = 0.36

Now, using the identity mentioned above:

cos^2 α = 1 - sin^2 α cos^2 α = 1 - 0.36 cos^2 α = 0.64

To find cos α, we take the square root of both sides. However, since α lies in the second quadrant (π < α < 3π/2) where cos α is negative, we'll take the negative square root:

cos α = -√0.64 cos α = -0.8

So, the value of cos α is -0.8.