Answer:
8x
Step-by-step explanation:
72 divided by 8 = t
x=30o+n90on∈Z
cos2x=sin(90o−2x)=sin(2x−30o)
Which mean 90o−2x=2x−30o+n360o
or 90o−2x+2x−30o=(2n+1)180o
The later cannot be true.
so x=30o+n90on∈Z