Michael J. answered 07/23/17
Tutor
5
(5)
Mathematical Reasoning and Logic Application
Set cos((π/4)x) = 0
Set the argument equal to angles that make cosine zero.
(π/4)x = π/2 , (π/4)x = 3π/2 , (π/4)x = (5π/2)
x = 2 , x = 3/2 , x = 5/2