00:01
Okay, number 72, we want to graph, wait one second, y equals 2 cosine 3x minus pi over 4 plus 1.
00:16
Okay, this is complicated one.
00:19
Now 2 is easy to deal with, plus 1, it's easy to deal with, you just need to shift the whole graph 1 unit up.
00:28
This one, you just need to stretch it.
00:32
Make the amplitude to be 2.
00:35
Now, okay, here we have, we want to know the period.
00:40
The period is 2 pi over b.
00:43
B is 3 here.
00:44
So the period is 2 pi over 3 now.
00:48
And we got negative subtract pi over 4.
00:56
So we want to shift the graph to the...
01:03
Right side, pi over 4 divide by b, which is 3.
01:11
So equals pi over 12, shift pi over 12 to the right side, to the right side.
01:19
And that's it.
01:21
So if we draw cosine x, cosine x is something like that.
01:28
We have 2 pi.
01:32
And this one is pi.
01:33
This one is pi over two, three pi over two.
01:41
Now the period is two pi over three now, so we want to divide each of those by three.
01:47
So this is two pi over three, this is three pi over six, pi over six, pi over three.
01:54
And we want to shift this graph, pi over 12 unit to the right, so something somewhere here, to the right.
02:08
So we can move this axis to the left, right? so your axis is here now.
02:19
This one is going to be, this part is going to be pi over 12...