identify the inflection points and local maxima and minima of the function below and its associated graph…

identify the inflection points and local maxima and minima of the function below and its associated graph. identify the open intervals on which the function is differentiable and is concave up and concave down.\n\n( y = \frac { 3 } { 11 } ( x ^ { 2 } - 9 ) ^ { \frac { 2 } { 3 } } )\n\nfind the inflection points of the curve. select the correct choice below and, if necessary, fill in the answer box to complete your choice.\n\na. the inflection point(s) is/are\n(type an ordered pair. type an exact answer, using radicals as needed. use a comma to separate answers as needed.)\nb. there are no inflection points.
Answer
Explanation:
Step1: Find the first derivative
Use the chain rule (y = \frac{3}{11}(x^{2}-9)^{\frac{2}{3}}), let (u=x^{2}-9), then (y=\frac{3}{11}u^{\frac{2}{3}}). The derivative of (y) with respect to (u) is (y_{u}=\frac{3}{11}\times\frac{2}{3}u^{-\frac{1}{3}}=\frac{2}{11}u^{-\frac{1}{3}}), and the derivative of (u) with respect to (x) is (u_{x} = 2x). By the chain rule (y^{\prime}=\frac{2}{11}(x^{2}-9)^{-\frac{1}{3}}\times2x=\frac{4x}{11(x^{2}-9)^{\frac{1}{3}}}).
Step2: Find the second derivative
Use the quotient rule ((\frac{f}{g})^{\prime}=\frac{f^{\prime}g - fg^{\prime}}{g^{2}}), where (f = 4x), (f^{\prime}=4), (g = 11(x^{2}-9)^{\frac{1}{3}}), (g^{\prime}=11\times\frac{1}{3}(x^{2}-9)^{-\frac{2}{3}}\times2x=\frac{22x}{3}(x^{2}-9)^{-\frac{2}{3}}). (y^{\prime\prime}=\frac{4\times11(x^{2}-9)^{\frac{1}{3}}-4x\times\frac{22x}{3}(x^{2}-9)^{-\frac{2}{3}}}{121(x^{2}-9)^{\frac{2}{3}}}) Multiply numerator and denominator by (3(x^{2}-9)^{\frac{2}{3}}) to get: (y^{\prime\prime}=\frac{132(x^{2}-9)-88x^{2}}{363(x^{2}-9)^{\frac{4}{3}}}=\frac{132x^{2}-1188 - 88x^{2}}{363(x^{2}-9)^{\frac{4}{3}}}=\frac{44x^{2}-1188}{363(x^{2}-9)^{\frac{4}{3}}}=\frac{44(x^{2}-27)}{363(x^{2}-9)^{\frac{4}{3}}}=\frac{4(x^{2}-27)}{27(x^{2}-9)^{\frac{4}{3}}})
Step3: Find inflection points
Set (y^{\prime\prime}=0), then (x^{2}-27 = 0), so (x=\pm3\sqrt{3}). When (x = 3\sqrt{3}), (y=\frac{3}{11}((3\sqrt{3})^{2}-9)^{\frac{2}{3}}=\frac{3}{11}(27 - 9)^{\frac{2}{3}}=\frac{3}{11}(18)^{\frac{2}{3}}) When (x=-3\sqrt{3}), (y=\frac{3}{11}((- 3\sqrt{3})^{2}-9)^{\frac{2}{3}}=\frac{3}{11}(27 - 9)^{\frac{2}{3}}=\frac{3}{11}(18)^{\frac{2}{3}})
Answer:
A. The inflection point(s) is/are ((-3\sqrt{3},\frac{3}{11}(18)^{\frac{2}{3}}),(3\sqrt{3},\frac{3}{11}(18)^{\frac{2}{3}}))