How do you do Partial Fractions with 2nd degree denomincator?

How do you do partial fractions if the denominator has 2nd degree terms (I know the basic method)?

My textbook says:

Using partial fractions we get

Since I have to check every single thing my textbook says (it's in my genes or something):

Comparing numerator's coefficients implies that:

and therefore:

which is quite clearly wrong.

*What'd I do wrong? How do I get an s term in the numerator?*

Thanks.

Re: How do you do Partial Fractions with 2nd degree denomincator?

Quote:

Originally Posted by

**MSUMathStdnt** How do you do partial fractions if the denominator has 2nd degree terms (I know the basic method)?

My textbook says:

Using partial fractions we get

Since I have to check every single thing my textbook says (it's in my genes or something):

Comparing numerator's coefficients implies that:

and therefore:

which is quite clearly wrong.

*What'd I do wrong? How do I get an s term in the numerator?*

Thanks.

Read the *Procedure* here:

Partial fraction - Wikipedia, the free encyclopedia

Find A,B,C and D.

Re: How do you do Partial Fractions with 2nd degree denomincator?

I'v done it like this:

So and so and

So:

Check:

It seems to work.

EDIT:

In my opinion I don't think it's pre-algebra stuff.

Re: How do you do Partial Fractions with 2nd degree denomincator?

Quote:

Originally Posted by

**Siron** I'v done it like this:

So

and

so

and

So:

Check:

It

__seems__ to work.

Okay, but why?

Re: How do you do Partial Fractions with 2nd degree denomincator?

Do you ask me why it's working? ...

Re: How do you do Partial Fractions with 2nd degree denomincator?

Quote:

Originally Posted by

**Siron** Do you ask me why it's working? ...

Maybe...

If you had to write as sum of partial fraction, what would you do? and if it was ?

Re: How do you do Partial Fractions with 2nd degree denomincator?

I would rewrite:

Re: How do you do Partial Fractions with 2nd degree denomincator?

@Also sprach zarathrusta:

Or was the question not mentioned to me? ...