Please show work, thank you! :))

Question 18 (2 points) Find the point of inflection, if it exists, for the function y = 3x3 - 4. State the x- coordinate and the y-coordinate to the nearest whole number. Par... B v + =122 Question 19 (2 points) Determine the interval where the curve defined by f(x) = 2x - 6x2 - 32x + 3 is concave up or concave down