can i have help on 1, 2 and 3

webassign.net C UPDATES AVAILABLE 9:25 AM A Quiz 7 (3.4 - 3.5) - Math 1411, section 16228 LG, Fall 2021 | WebAssign Do you want to install the updates now or try tonight? Your last submission is used for your score. time left... 1:24:26 1. [-/1 Points] DETAILS LARCALC11 3.4.015. MY NOTES ASK YOUR TEACHER 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 = 7x - 8 tan x, (- 72) concave upward concave downward 2. [-/1 Points] DETAILS LARCALC11 3.4.027.MI. MY NOTES ASK YOUR TEACHER Find the point of inflection of the graph of the function. (If an answer does not exist, enter DNE.) f( x ) = sin , [0, 4x] ( 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 3. [-/1 Points] DETAILS LARCALC11 3.4.065.MI. MY NOTES ASK YOUR TEACHER 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