# Finding the domain of this function

1. Apr 26, 2013

### nothingsus

1. The problem statement, all variables and given/known data
Find the domain of 1/(sqrt(2x)-1)2
Note: the minus one is not included under the square root

2. Relevant equations
Title

3. The attempt at a solution

So the denominator cannot be zero

so that means that sqrt(2x) cannot equal 1
x cannot be 1/2

letting the denominator be greater than 0 gets me x is greater than 1/2

my calculator says x is equal to or greater than 0 but cannot be 1/2

Where did the equal to greater than 0 part come from?

2. Apr 26, 2013

### Staff: Mentor

From the square root. The argument of a square root can't be negative, so you need 2x ≥ 0.

3. Apr 26, 2013

### SammyS

Staff Emeritus
Why are you concerned about the denominator being greater than zero?

4. May 8, 2013

### csleong

The simplest way is, with the answer provided, plug in x=-1 and x=1/2 and you should know why.

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