SOLUTION: find the domain in interval notation of f(x)= square root x^2-16 over x^2+5x+4?

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Question 427490: find the domain in interval notation of f(x)= square root x^2-16 over x^2+5x+4?
Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
Solution:Since this is an rational function from its domain must rejected the values of x that make denominator zero. First factor the denominator:
f%28x%29=%28sqrt%28x%5E2-16%29%29%2F%28x%2B4%29%28x%2B1%29%29
(x+4)(x+1)=0 => x+4=0 =>x=-4 and x+1=0 => x=-1 For this two values of x our function is undefined. Thus, its domain are the intervals:
( -infinity, -4), ( -4, -1 ), ( -1, +infinity ) or all real numbers different fro -4 and -1.