Hi,

I hope someone can help. I'm suppose to state two intervals where the function y = 3cos(4x)-4 has an AROC that is zero. I'm wondering why my textbook only gave the solution of 0 < x < pi/2, and pi < x < 3pi/2 ? Wouldn't the two intervals 0 < x < pi/2, and pi/2 < x < pi be just as correct?

Please let me know!

Sincerely,

Olivia