Question

The graph of which function passes through (0,3) and has an amplitude of 3?

Answer 1

The choices are supposed to be
f(x) = sin x + 3
f(x) = cos x + 3 
f(x) = 3 sin x
f(x) = 3 cos x

The amplitude is the value of the numerical coefficient of sin or cos. The only possible answers are
f(x) = 3 sin x
f(x) = 3 cos x

Next, the function must pass through the point (0,3)
3 sin 0 = 0 and
3 cos = 3

Therefore, the answer is
f(x) = 3 cos x<span />

Answer 2

The answer is f(x)=3cos(x)