Answer:
I don't know the answer to this question
Answer: The amplitude is 4.
Step-by-step explanation:
Given the form of the sine function:

Where
is the amplitude,
is the period and "k" is the vertical shift of the wave.
You know that, in the sine function given (
), you can identify the amplitude and the period. These are:


Therefore, the amplitude of
is:

Equation: 15 + 6t = 81
Work: 15 + 6t = 81
-15 -15
6t = 66
t = 11