PLEASE DO NOT USE A CALCULATOR AND PLEASE SHOW ALL WORK. NO CALCULATOR PLEASE. SHOW ALL WORK

D Question 7 20 p Find the number 'b' such that the average value of f(x) = 1 - 4x + 9x2 on the interval [0, b] is equal to 2 Upload Choose a File D Question 8 20 p Find the exact length of the curve 2x2 - -In(x) for 1s xse Upload Choose a File D Question 9 20 pts Find the exact area of the surface obtained by rotating the curve about the x-axis. x = =7(2 + 2)3 for 0 sysn