
Show transcribed image text Determine the values of x where f(x) has a horizontal tangent line. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) /(x) = (x2 + 9)(2x-12)
Determine the values of x where f(x) has a horizontal tangent line. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) /(x) = (x2 + 9)(2x-12)





