Estimate the area between the x-axis at the curve f (x) = x 1 1 from x = 1 to x = 13 using: + (a) (1 pt) a left-hand sum with it = 4. Is this estimate an overestimate or underestimate? (b) (1 pt) a right-hand sum with it = 4. Is this estimate an overestimate or underestimate? (c) (1 pt) a midpoint sum with it = 4. Is this estimate an overestimate or underestimate? (d) (2 pts) Write the formula for FL (the right-endpoint sum with it rectangles) using sigma notation.