SOLUTION: Find the domain of f(x)=sqrt x-4. thanks

Algebra.Com
Question 202032: Find the domain of f(x)=sqrt x-4. thanks




Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Start with the given expression

Remember you cannot take the square root of a negative value. So that means the argument must be greater than or equal to zero (i.e. the argument must be non-negative)

Set the inner expression greater than or equal to zero

Add 4 to both sides


Combine like terms on the right side


So that means x must be greater than or equal to in order for x to be in the domain

So the domain in set-builder notation is


So here is the domain in interval notation: [4,)



Notice if we graph , we get
notice how the graph never crosses the line . So this graphically verifies our answer.

and we can see that x must be greater than or equal to in order to lie on the graph

RELATED QUESTIONS

Find the domain of f(x)=... (answered by wgunther)
Find the domain of the function: f(x)=sqrt(9-x^2)... (answered by robertb,edjones)
Find the domain for f(x)= {{{(sqrt(5-x)+sqrt(x-1))/(x-2)sqrt(x)}}} Thanks for any... (answered by lynnlo,stanbon)
find the domain of f(x)= sqrt{x^2 -... (answered by bucky)
find the domain of f(x) =... (answered by ReadingBoosters)
Find the domain of f(x) =... (answered by tommyt3rd)
find the Domain of f(x) = sqrt(sec... (answered by ikleyn)
f(x)=sqrt -5x+4 find the domain. (answered by Nate)
How do you find the domain of f. Given the function... (answered by solver91311,reviewermath)