How do you find the coordinates of the terminal points corresponding to the following arc length on the unit circle: 4π/3?

1 Answer
May 21, 2015

Use the trig unit circle as proof. The coordinates of the arc's terminal point are:

x = cos (4pi)/3 = cos (pi/3 + pi) = -cos (pi/3) = -1/2x=cos(4π)3=cos(π3+π)=cos(π3)=12 (Quadrant III)

y = sin ((4pi)/3) = sin (pi/3 + pi) = - sin (pi/3) = (-sqrt3)/2y=sin(4π3)=sin(π3+π)=sin(π3)=32-