What is the domain of f(x)=9−x2f(x) = \sqrt{9 - x^2}f(x)=9−x2?
x≤3x \leq 3x≤3
−3≤x≤3-3 \leq x \leq 3−3≤x≤3
x≥−3x \geq -3x≥−3
All real numbers