00:02
For number 41, we are given this graph and we're asked to find the cosine function and the sign function.
00:08
So it's a little blurry, but you can tell where the values end.
00:14
This is ending at 1, this is a 1, and this is a negative 3.
00:29
So to start off, we will do the cosine function, so cosine function.
00:39
And the general formula for this is y equals a cosine b x minus h plus k so now we have to find a and to find a we do one half times the maximum minus the minimum value so the maximum in this case is one since it goes all the way up to one and the minimum is minus three so we get 2.
01:25
And then to find b, we would do b equals 2 pi over the period.
01:34
And in this case, the period is 2 pi.
01:48
So b is 1.
01:57
And our h value is just how high it is.
02:05
And in this case, our h is pi over 3.
02:10
Since this point occurs at pi over 3...