Question

Найдите sin A, если: а) cos A=1/2,

Answer 1

CosA=1/2, а это значит что A=60°
sinA=0.86

Answer 2

To find sin A when cos A = 1/2, we can use the Pythagorean identity:

sin^2 A + cos^2 A = 1

Since we know that cos A = 1/2, we can substitute it into the Pythagorean identity:

sin^2 A + (1/2)^2 = 1

Now, we solve for sin A:

sin^2 A + 1/4 = 1

Subtract 1/4 from both sides:

sin^2 A = 1 - 1/4

sin^2 A = 3/4

Now, take the square root of both sides:

sin A = ±√(3/4)

Since sine is positive in the first and second quadrants, sin A = √(3/4).

However, √(3/4) can be simplified further:

√(3/4) = √3 / √4 = √3 / 2

So, the value of sin A is √3 / 2.