SubArea: Analyzing function behaviorLevel: AProject ID: 9000079103Accepted: 1Clonable: 0Easy: 0Find the $x$ at which has the function $f$ a local maximum. \[ f(x) = x^{3} - 3x^{2} - 9x + 2 \]\(x=- 1\)\(x=- 3\)\(x=1\)\(x=3\)
