Find the Domain f(x) = square root of x^2-4
Problem
Solution
Identify the restriction for a square root function, which requires the radicand (the expression inside the square root) to be greater than or equal to zero.
Factor the quadratic expression using the difference of squares formula.
Determine the critical points by setting each factor to zero, which gives
x=2 andx=−2 Test the intervals created by the critical points:
(−∞,−2] [−2,2] and[2,∞) Evaluate the sign of the product in each interval. For
x=−3 (−5)*(−1)=5≥0 (True). Forx=0 (−2)*(2)=−4≥0 (False). Forx=3 (1)*(5)=5≥0 (True).Combine the intervals where the inequality holds true to define the domain.
Final Answer
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