Six Trigonometric Functions

Question

If cos(θ)=−√3/2, find all the angles which satisfy the given equation and condition.

Raymond B. · Accepted Answer

theta is in quadrant II or III, the only quadrants where cosines are negative

the reference angle is 30 degrees or pi/6

In quadrant II that's 5pi/6, in quadrant III it's 7pi/6, that's pi + or - p/i/6

then add 2npi to each where n= any integer

that gives an infinite number of angles that satisfy cos(theta) = -sqr3/2

1 Expert Answer