(Solved): For y=2x3+18x24x, determine concavity and the x-values where points of inflection occur. Do not ...

For $$y=2x^3+18x^2?4x$$, determine concavity and the $$x$$-values where points of inflection occur. Do not sketch the graph. On which interval(s) is the function concave down? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The function is concave down on (Type your answer in interval notation. Simplify your answer, including any radicals. Use integers or fractions for any numbers in the axpression.) B. There is no interval on which the function is concave down.