Answer:
amplitude is 1.5
Step-by-step explanation:
If amplitude of f(x) is a, the amplitude of f(cx + d) is also a, for any d and non-zero c.
If amplitude of f(x) is a, the amplitude of cf(x) + d is c*a, for any d and any c.
From that we know that amplitude of y=1.5sin4x is the same as amplitude of y=1.5sinx, and 1.5 times more than amplitude of y=sinx. And we know that amplitude of sinx is 1.
Thus, amplitude of y=1.5sin4x is 1.5
