00:01
So in this problem, fee is getting job offers from companies, and she's got two companies, company a and company b.
00:12
And they both start, both have starting salary at $32 ,000.
00:24
Then company a does an annual pay raise of $1 ,600, whereas company b does 4%.
00:35
So then we're asked a series of questions.
00:41
First one is, in what year will they be the same again? obviously they're same at the start, but not after that.
00:55
Okay, well, company a over time pays us a $32 ,000 plus $1 ,600 per year, right? t is obviously in years here.
01:14
Company b pays us the 32 ,000 times 4 % per year.
01:31
So now the question becomes, when are these equal? okay, well, let's see.
01:39
If i take 32 ,000 plus 1 ,600 t, set that equal to 32 ,000 times 1 .04 to the t.
01:51
I can divide by 32 ,000, right, everywhere.
01:58
I get one plus i have 1 ,600 divided by a 32 ,000, is 0 .05t, is equal to 1 .04 to the t.
02:17
Okay.
02:19
And now let's take the natural log of both sides and see what happens.
02:27
So i have ln of 1 plus, oh no, see ln of 1 plus 0 .05 t is equal to t ln 1 .04.
02:48
Right? okay.
02:58
Let's see, how do we get to that t though? that's the question.
03:08
Well, this is going to be a little tough in it to get to.
03:13
But there's an easier way to do this.
03:16
So let's go to our graphing calculator and let's graph.
03:19
This for a minute okay and so i went to desmonds .com brought down the graphing calculator and i put in the first formula which was 32 ,000 plus 1600 x all right and let's change our parameters here let's do zero to say 20 on the x and the y then we'll start at 32 thousand and we'll go to 50 ,000...