00:01
For this problem, we are told that the percentage of married women who earned more than their husbands over the period from 1960 through 2011 was growing at the rate of approximately r of t equals negative 0 .000000 -2 -2 -t squared plus 0 .0 -3 -8 for t between 0 and 51, where that's measured in percent per year in years t.
00:24
The percentage of married women earning more than their husbands in 1960 was 6 .2%.
00:30
For part a, we are asked to find an expression giving the approximate percentage of married women who earned more than their husbands in year t.
00:37
So that's just going to be the anti -derivative of little r there.
00:41
So i'm going to write this as p, i guess, for percentage.
00:46
Now, the antiderivative of the first term is that big coefficient times t cubed over three.
00:52
So negative 0 .000 -25142 times t cubed over 3.
01:00
Then we have the antiderivative of the second term is going to be that coefficient times t squared over 2.
01:07
That's 0 .02116 t squared over 2...