Question 308184
{{{y=sqrt(x-3)}}}


The domain of a function means essentially what values of x would be allowed in the graph.  You are NOT allowed to divide by zero, and in the real numbers you are not allowed to have a negative number inside a square root.  


With this in mind, in this problem you have a square root.  So, whatever you put in place of the x, you have to make sure that whatever is in the radical sign (in this case, x-3), it has to be greater than or equal to zero.


{{{x-3>=0}}}, which means that {{{x>=3}}}.  In interval notation, this is [3,inf).


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Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus