Question

find the exact trigonometric ratios for the angle whose radian measure is 4pi/3

Answer 1

well this is a 3rd quadrant angle

where tan is positive, sin and cos are both negative

in the 3rd quadrant, the angles are

\[\pi + x\]

then you know

\[\frac{4\pi}{3} = \pi + x\]

find the value of x,

the you need to find

tan(x), -sin(x) and -cos(x)

they will all be exact values

Answer 2

to get the values draw a triangle