00:01
To integrate this, we first want to find the partial fraction decomposition for x squared minus x minus 8 over x plus 1 times x squared plus 5x plus 6.
00:11
Now, x squared minus x minus 8 over x plus 1 times x squared plus 5x plus 6, this can be rewritten into x squared minus x minus 8 over x plus 1 times x squared plus 6.
00:30
2 times x plus 3 and since the denominator has distinct linear factors then the partial fractions will have denominators x plus 1 x plus 2 and x plus 3 now since all of them are linear the numerator will be constant so that'll be a and here we have b and then here we have c now to find a b and first want to multiply this by its lcd x plus 1 times x plus 2 times x plus 3 and so we have x squared minus x minus 8 this is equal to a times x plus 2 times x plus 3 plus b times x plus 1 times x plus 3 plus we have c times x plus 1 times x plus 2.
01:30
Now if, let's say, x plus 1 equals 0, that means x is negative 1, then we have negative 1 square that's 1 minus negative 1 minus 8.
01:44
This is equal to a times negative 1 plus 2, then negative 1 plus 3, plus we have b times 0 plus c times 0.
01:56
So this gives us negative 6 equal to 2a or a is just equal to negative 3...