could someone help me with this problem?

find 2 postive and 2 negative coterminal angles of -(pi)/4

3 answers

http://www.analyzemath.com/Angle/coterminal_angle.html

Just add k*2PI (or subtract).

k = 1,2,3....
Coterminal angles are angles which, drawn in standard position, share a terminal side.

The initial side of measurements is always the x-axis (0 degree), and the terminal side is where the measurement of the angle is to be made.

So some of the coterminal angles of 60 degress are 420°, 780° -300° or -660°. A positive coterminal angle for -π/4 would be 7π/4. A negative one would be -9π/4.

You would be sure to find other ones as required.
find positive and negative coterminal angle for 55(pi)/18