00:01
Hi, in this question we're given this function g of x, a sinusoidal function, and we want to answer some things about it.
00:08
So the first thing we want to say is what's the amplitude, and this is controlled simply by this number here, multiplied out front.
00:20
So we see that the amplitude is 7.
00:25
Then for the period, this is given by the coefficient of the x in the sine function, but then we divide it by 2 pi.
00:34
So it's going to be 5 pi over 8, divided by 2 pi, so that's 5 over 16.
00:43
And then we want the translated origin, so usually the origin is 0 ,0, but now we want to see sort of where this starts.
00:56
So the first thing we have to do is to solve 5 pi over 8 x plus 9 pi over 16 equals 0.
01:06
So this gives us x equals negative 9 pi over 16 over 5 pi over 8.
01:16
So the pi's cancel, we get negative 9 over 5 times 8 over 16, so that's 1 over 2, so we get negative 9 over 10.
01:30
And then the y value is going to be translated by minus 4.
01:34
So the translated origin is going to be negative 9 over 10, comma, negative 4.
01:40
And then finally we want to sketch one period of this.
01:50
So let's do something like this.
01:54
So it's sort of centered at negative 4, and then it has a period of amplitude of 7, so it's going to go down to minus 11.
02:03
So that's like here, and then up to 3.
02:09
And then at negative 9 over 10, it's going to sort of start here.
02:18
Hi...