Math Is Fun Forum

Avva

Member

Registered: 2009-02-25

Posts: 41

help me find the domain

FIND the Domain :
1. f(x)=square root (x-2) - cubic root (x+3)
2. f(x)=x^2-x-1 ÷ (square root (x-2) - 5)
PLZ explain ur ans

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: help me find the domain

Hi avva;

1) For

the domain is all real numbers x >= 2 :

Less than 2 the first radical will be complex.

2) If you mean this:

Its defined for  x>= 2 and  x ≠ 27 so the domain is x>= 2 and  x ≠ 27.

Less than 2 the radical in the denominator becomes complex and when x = 27 the denominator is zero.

Last edited by bobbym (2009-09-20 18:50:37)

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Avva

Member

Registered: 2009-02-25

Posts: 41

Re: help me find the domain

thanks 4 replying me

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: help me find the domain

Hi Avva;

Glad to help, bring more!

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.