SOLUTION: Please help me find the domain to this function {{{g(x)=sqrt(x^2-2x-8)}}}

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Question 468408: Please help me find the domain to this function
g%28x%29=sqrt%28x%5E2-2x-8%29
Found 2 solutions by edjones, lwsshak3:
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
g(x)=sqrt(x^2-2x-8) The square root cannot be less than zero.
(x-4)(x+2)=0
x=4, x=-2
(-infinity, -2] U [+2, infinity)
.
Ed

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Please help me find the domain to this function
sqrt(x^2-2x-8)
..
The expression inside a radical must always be ≥0
x^2-2x-8≥0
f(x)=(x-4)(x+2)≥0
If x≥4, f(x)≥0
If x≤2, f(x)≥0
If x<4, f(x)<0
If x>2, f(x)<0
Domain: (-∞,2] U [4,∞)