00:01
I'll start by taking the partial fraction decomposition of the integrand.
00:05
So we have 2 over x plus 5 squared times x minus 1.
00:11
We can write this as some constant a over x plus 5 plus some constant b over x plus 5 squared plus some constant c over x minus 1.
00:24
So if i multiply this equation by the denominator on both sides, i get 2 is a times x plus 5 times x minus 1 plus b times x minus 1 plus c times x plus 5 squared.
00:41
We have 2 equals ax squared plus 4ax minus 5a plus bx minus b plus cx squared plus 10cx plus 25c.
01:00
So let's combine like terms.
01:03
We have a plus b times c, sorry times, let's start over.
01:10
A plus c times x squared plus 4a plus b plus 10c times x plus negative 5a minus b plus 25c.
01:27
Okay, so on the left hand side there are no terms with x squared, so this coefficient needs to be zero.
01:33
There are also no terms with x, so this coefficient needs to be zero.
01:39
And these constants need to equal 2.
01:42
So we have a plus c equals zero, 4a plus b plus 10c equals zero, and negative 5a minus b plus 25c equals 2.
01:58
Okay, so let's solve for a.
02:03
A is negative c.
02:04
I'll plug that into this equation...