SOLUTION: Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.) square root of x^2 − 16 I squa

Algebra ->  Inequalities -> SOLUTION: Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.) square root of x^2 − 16 I squa      Log On


   

Question 992342: Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.)
square root of x^2 − 16

I squared the entire thing, so that took care of the square root. Then I factored it into (x-4) (x+4) but thats as far as I got...
help, please? :(
Found 2 solutions by stanbon, ikleyn:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Determine the values of the variable for which the expression is defined as a real number. (Enter your answer using interval notation.)
square root of x^2 − 16
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sqrt(x^2-16)
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For the value to be a Real Number, x^2-16 must be >= 0
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Solve:
x^2-16 >= 0
(x-4)(x+4) >= 0
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Ans: x >= 4 or x <= -4
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Cheers,
Stan H.
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Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
Many similar examples are considered in the lesson  Domain of a function which involves a quadratic polynomial under the square root operator  in this site.

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