Is this right so far?...what do I do next?

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- March 7th 2010, 05:00 PMpurplec16Identities

Is this right so far?...what do I do next? - March 7th 2010, 05:27 PMskeeter

- March 7th 2010, 06:05 PMpurplec16
Thanks so much, how do u you understand how to do these things, when you do it I undestand, but when the question is there on its own I dont know what to do, I guess it calls for a lot of practice

- March 7th 2010, 06:09 PMskeeter
- March 7th 2010, 06:39 PMArchie Meade
Hi purplec16,

you can start to reason it through a little also...

We can write out the definitions for the terms on the right hand side...

Now we see we need to have under the line on the left hand side,

therefore as we can only multiply by 1 (so the ratio stays the same),

we multiply the left hand side by

as this gets us that term in the denominator,

however we see later on, that this term comes in anyway, so it ends up being unnecessary!

Now we are not supposed to have under the line

so we need to fish that out!

We therefore multiply by 1 again, this time using the "conjugate" of

because

which is

Therefore