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#1 2009-02-07 22:54:08
- Bye Thagoras!
- Guest
Factoring
Hi,
How would I solve this?
(x-25)/sqrt(x)-5
This is for a limit question (as x approaches 25) but I am just stuck on the simplifying bit 
Is there some sort of rule for when you have x/sqrt(x)?
#2 2009-02-07 23:08:25
- Jai Ganesh
- Administrator
- Registered: 2005-06-28
- Posts: 48,045
Re: Factoring
If the question is
then, the expression can be re-written as
,
or
.
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
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#3 2009-02-08 01:49:45
- mathsyperson
- Moderator
- Registered: 2005-06-22
- Posts: 4,900
Re: Factoring
Sometimes it helps to use a substitution to get rid of surds. If you said t = √x, then you'd get:
You might then find that easier to factorise.
(Remember to get it back in terms of x when you're finished though)
Why did the vector cross the road?
It wanted to be normal.
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