Question

On the unit circle, where 0 < theta < or equal to 2pi, when is tan theta undefined?

A. Theta=pi and theta=2pi
B. sin theta = cos theta
C. theta = pi/2 and theta=3pi/2
D. sin theta = 1/cos theta

Please answer within 5 minutes, this is timed.

Answer 1

Answer: it is C

Explanation:

Answer 2

The tangent is the slope so is undefined when there's no slope, which means a vertical angle, 90 degrees or -90 degrees aka 270 degrees.

In radians that's pi/2 and 3pi/2, choice C