Change the cartesian coordinate point (-3,4) to polar.
I get r=5
and im getting theta = -53.13
my textbook says its supposed to be 126.9
+36915 Tan = -4/3
Arctan(-4/3) = -53.130102354156+180 = 126.869897645844
-53 is the reference angle between - pi/2 and + pi/2 so....
Think about the coordinate plane the point -3 , 4 is in Quadrant 2 and the answer is 126.87 degrees
