00:01
Okay, we'd be given this partial fraction.
00:03
Oh, we've given this fraction and we'd like to put it into partial fraction form.
00:06
Clearly you can take an x cubed out of this and you'll be left in x plus 1.
00:09
So we're going to have to have one fraction with an x, one fraction with an x squared, one, missed off my squared there, one fraction with an x cubed, and then one fraction with our x plus 1.
00:24
So expanding this out, we're going to have 2x cubed plus x squared, minus x minus 1 is equal to a times by x squared times by x plus 1 plus b times by x that's supposed to be a cube by the way times by x times x plus 1 then just c lots of x plus 1 and then d of x cubed so first things first we can work out of c because it's the only one with the year unit section because everything else is going to be times by an x.
01:03
So what you could do just put zero if your x value, this bill will be zero, this put be zero, this is zero, so you're just going to have c is equal to minus one.
01:15
That one was nice and easy.
01:16
The other one we can do nice and easy is x is equal to minus one because we're getting rid of our a, b's and c's and just have our d and we'll be left with minus d because it's x cubed.
01:24
And that's going to be equal to well minus one cubed.
01:26
It's going to be minus one.
01:27
So that's minus two...