00:01
All right, so we have an alternating current, which is an ac current as opposed to a dc current, which is direct current.
00:09
And so the current as a function of t is 2 cosine plus 2 sine t in amps.
00:24
And we want to find the peak current for the circuit, or in other words, the absolute maximum of this function.
00:30
So this function has domain, all real numbers.
00:36
Its derivative is going to be negative 2, sine, t, plus 2, cosine, t.
00:44
So the derivative's never undefined, but it can be 0.
00:48
So when is i prime of t equal to 0? well, it's when negative 2, sine t plus 2 cosine t is 0.
01:00
In other words, we just want sine of t to be equal cosine...