List four positive real-number values of t for which cos t=0
So we know that cosine is the x-axis. So cosine at 0, and they want me to list four positive real number values? So It could be 0,0 , 0, pi/2, 0,pi , and 3pi/2
The answer in the book has pi/2, 3pi/2, 5pi/2, 7pi/2...