Let f(x) = √9-x^2 Then, dom (f) = ?

Question

Mark (√) against the correct answer in the following:

Let \(f(x)=\sqrt{9-x^2}\) Then, dom (f) = ?

A. [ - 3, 3]

B. [ - ∞, - 3]

C. [3, ∞)

D. ( - ∞, - 3] ∪ (4, ∞)

Answer 1

Correct Answer is (A) [ - 3, 3]

\(f(x)=\sqrt{9-x^2}\)

\(\sqrt{9-x^2}\) should be ≥ 0

\(\Rightarrow 9-x^2\geq0\)

\(\Rightarrow x^2\leq9\)

\(\Rightarrow -3\leq x\leq3\)

∴dom(f) = [ - 3, 3]