Answer:
-5
Step-by-step explanation:
f(x) = 5 cos ( 3x)
f(60) means let x = 60
f(60) = 5 cos ( 3*60)
= 5 cos (180)
= 5 (-1)
= -5
Answer: -5
5cos 3x60
5cos 60
5 x (-1) = -5
