Question 74039
<pre><font size = 5><b>
FIND THE DOMAIN FOR {{{f(x) = sqrt(3x+21)}}},
AND EXPRESS IT USING INTERVAL NOTATION.

        {{{f(x) = sqrt(3x+21)}}}

The {{{3x+21}}} is under a square root radical, and
we must never have a negative number under a
square root (or any EVEN root) radical. So
we must set {{{3x+21>=0}}}
              {{{3x>=-21}}} 
               {{{x>=-7}}}

Interval notation for that is [-7,<font face = "symbol">¥</font>)

Edwin</pre>