SOLUTION: <pre>FIND THE DOMAIN FOR {{{f(x) = sqrt(3x+21)}}}, AND EXPRESS IT USING INTERVAL NOTATION., AND EXPRESS IT USING INTERVAL NOTATION.

Algebra ->  Functions -> SOLUTION: <pre>FIND THE DOMAIN FOR {{{f(x) = sqrt(3x+21)}}}, AND EXPRESS IT USING INTERVAL NOTATION., AND EXPRESS IT USING INTERVAL NOTATION.       Log On


   

Question 74039: 
FIND THE DOMAIN FOR f%28x%29+=+sqrt%283x%2B21%29,

AND EXPRESS IT USING INTERVAL NOTATION., AND EXPRESS IT USING INTERVAL NOTATION.  

Answer by Edwin McCravy(20054) About Me  (Show Source): 

You can put this solution on YOUR website!
 

FIND THE DOMAIN FOR f%28x%29+=+sqrt%283x%2B21%29,
AND EXPRESS IT USING INTERVAL NOTATION.

        f%28x%29+=+sqrt%283x%2B21%29

The 3x%2B21 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%2B21%3E=0
              3x%3E=-21 
               x%3E=-7

Interval notation for that is [-7,¥)

Edwin