Question

Suppose that P is the point on the unit circle obtained by rotating the initial ray counterclockwise through 330 degrees. Find the measure of the reference angle for 330°, and then find sin(330°) and cos(330°).

Answer 1

Reference angle will be 30°

sin(330°) will be equal to
`(-1)/(2)`

cos(330°) will be equal to 0.866

Explanation:

We have given angle is 330°

As the angle
`330^(\circ)` is in forth quadrant

We know that in forth quadrant the reference angle is given by

Reference angle
`=360-angle`

As the angle is 330°

So the reference angle will be
`=360-330=30^(\circ)`

Now we have to find the value of

sin(330°)
`=sin(2\pi -30)=-sin(30)=(-1)/(2)`

And now
`cos(330^(\circ))=cos(2\pi -30)=cos30=0.866`