tan 2 x = -1
tan is negative in quadrants 2 and 4
2x = 135, 315, 495, 675
now divide those by 2
solve for x, 0 ¡Ü x < 360
tan2x+1=0
My answers: 22.5, 157.5, 202.5, 337.5
Textbook: 67.5, 157.5, 247.5, 337.5
I don't understand. Am I wrong?
Thanks for your help.
1 answer