Question

Cos a, если sin a = -4/5

Answer 1

Ответ:

На фото

Пошаговое объяснение:

Answer 2

To find the value of cos(a) given sin(a) = -4/5, we can use the Pythagorean trigonometric identity, which states:

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

Since we know sin(a) = -4/5, we can substitute this value into the equation:

(-4/5)^2 + cos^2(a) = 1

Solving for cos(a):

(16/25) + cos^2(a) = 1

Now, isolate cos^2(a):

cos^2(a) = 1 - 16/25

cos^2(a) = (25 - 16) / 25

cos^2(a) = 9/25

Finally, take the square root to get the value of cos(a):

cos(a) = ±√(9/25)

cos(a) = ±(3/5)

So, cos(a) can have two possible values: 3/5 or -3/5, depending on the quadrant in which angle a lies. To determine the sign, we need more information about the specific quadrant in which the angle is located.