Question

If cos A = sqrt(3)/2 and 0 <= A <= 360, find the possible measures of angle A.

Answer 1

since cosA is positive, angle A has to be in the quadrant I or IV.
so A=30 degrees or 330 degrees

Answer 2

Could you tell how you would be able to obtain 30 degrees and 330 degrees without a calculator @dpaInc

Answer 3

do you have the unit circle?

Answer 4

Yes I do.

Answer 5

Actually, I won't have the unit circle drawn for me on a test.

Answer 6

cosine of an angle refers to the x-coordinate of the point on the unit circle. the angle that corresponds with the points that have an x-coordinate of (sqrt3)/2 is 30 degrees or 330 degrees.

Answer 7

memorize the unit circle if you won't have with you on a test. they basically deal with two special triangles...

30-60-90 triangle
45-45-90 triangle