can i get help on 1,2 and 3

[I1 Points] LARCALC1 1 3.4.01 5. ASK YOUR TEACH MY NOTES Determine the open intervals on which the graph is concave upward or concave downward. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) y=7X8tanx, (,:) 2 2 concave upward concave downward [-I1 Points] LARGLC11 3.4.027.MI. ASK YOUR TEACH Find the point of inflection of the graph of the function. (If an answer does not exist, enter DNE.) f(x) = sin %, [0, 47!] (x.y)=( ) Describe the concavity of the graph of the function. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) concave upward concave downward {-11 Points] LARCALC11 3.4.065.MI. ASK YOUR TEACH A manufacturer has determined that the total cost C of operating a factory is C : 1.5x2 + 45x+ 15000, where X is the number of units produced. At what level of production will the average cost per unit be minimized? (The average cost per unit is C/x.) x = units