QUESTION 3 a) b) The volume of an open cylindrical tank is 100 n13 . Given that r is the radius of the circular base and h is the height of the tank. i) Show that the total surface area of the tank is given by A = m2 + w . i" ii) Find the vaiue of r and it that will minimize the total surface area of the tank. (8 marks) 3X2 Consider a function f(x) = x + ? 2x + 5 . E) Find the interval(s) where the function f(x) is increasing or decreasing. ii) Find the intervai(s) where the function f(x) is concave upward or downward. (8 marks) The Mean-Value Theorem for differentiation states that if f (x) is differentiable on (ab) and continuous on [a,b], then there is at ieast one point 0 in (a,b) where mil-"(3) f'(c)= ba If f(x)=, nd the exact value of c in the interval (1,2) that satises the above x theorem. (4 marks)