D(t) = 50 – 23 sin (11 (t +0.23)).

After she starts measuring, when is the first time the depth of the waves is at its average value? Give an exact

answer.

0.0566 units of time

Step-by-step explanation:

The average value for the depth of the waves is 50 and occurs when sin (11 (t +0.23)) = 0. It is known that sin(π) = 0, therefore:

Since the units of time used were not specified, the first time the depth of the waves is at its average value is 0.0566 units of time after she starts measuring.