Where does the graph of y = tan theta intersects the graph of y = -1.
Trigonometry - Damon, Sunday, March 7, 2010 at 8:51pm
tan 45 degrees = 1, now worry about the quadrant (x and y different signs)
You are asking when tan theta = -1
that is at 90+45 degrees
and at 270 + 45 degrees