00:03
All right, we're giving a function that models the growth or the spread of a flu, and we want to know how long until we reach 820 people, according to this model.
00:15
So that's our y value there.
00:17
So i'm going to set 820, and that is equal to 1 ,000, and then divided by 1 plus 990e to the negative 0 .70.
00:29
All right.
00:30
I'd kind of think about this as just cross multiplication.
00:33
So i'm going to get 820 times that thing is equal to 1 ,000.
00:38
So 820.
00:39
I'm not really going to multiply it through, at least not yet, times 1 plus 990e to the negative 0 .70.
00:48
All right.
00:48
And that's going to be equal to 1 ,000 times 1, which is just 1 ,000.
00:52
Divide both sides by the 820.
00:55
So i get 990e to the negative 0 .70.
00:59
So i'm going to get 1 ,000 divided by that 820.
01:04
Now i'm going to subtract one from both sides.
01:08
990e to the negative 0 .70 equals.
01:12
I can reduce this both by 10 pretty easily.
01:15
Just make that 100 divided by 82...