Question

What is the value of cos 4π/3?

A) -1/2 B) √3/2 C) - 1/√2 D) √3/2

Answer 1

Answer:

option A

.

.

.

.

.

.

hope it helps

Answer 2

Answer:

-1/2

Step-by-step explanation:

as we know how to convert radians to degree measure (simply by multiplying the radian measure by 180/π)

we get the degree angle as

=4π/3*180/π

=4*60

=240°

we don't know the measure of 240°

hence we will find reference angle which is

=360-240

=120°

and to make it more simpler 120's reference angle is 60 (180-120)..

but now need to consider the quadrant it lies in it lies in 2nd quadrant hence -ve

therefore the Vale of cos 4π/3 is -1/2