Note that normally we take . For this sort of example, we must use radians for the angle.

We have:

and .

So

So we can see that the amplitude is 13 A and this is the maximum value.

To find the first time that it occurs, we need to solve

That is

Now sin θ = 1 for the first time when . So we need to solve:

So the maximum value of 13 A will first occur at time t = 1.176 s.

We can see that this is correct from the graph: