I have solved 92% of the problem I just need help with one part

Let f(x) = 1 + 4x-. (a) Estimate the area under the graph of f, the x-axis, and the lines x = -1 and x = 2 using three rectangles and a right endpoints. R3 = 23 Improve your estimate by using six rectangles. 26 = 18.5 Sketch the curve and the approximationg rectangles for R3- y 15 15 15 15 10 10 10 10 51 5 -1 2 2 O-1 X 70-1 X 1 2 2 Sketch the curve and the approximationg rectangles for R 6- 15 - 15 15 15 - 10 10 10 10 5 5 5 51 O-1 -0.5 0.5 1 1.5 2 @0-1 -0.5 0.5 1 1.5 2 -1 -0.5 0.5 -0.5 1 0.5 1.5 2 1 1.5 2(b) Repeat part (a) using a left endpoints. L3 = 11 46 = 12.5 Sketch the curve and the approximationg rectangles for L3- 15 15 15 15 10 10 10 10 5 O- 2 N DO-1 O-1 1 2 Sketch the curve and the approximationg rectangles for L6- y 15 15 15 15 10/ 10 10 10 5 5 5 5 O-1 -0.5 0.5 1 1.5 2 70-1 -0.5 0.5 1 1.5 2 -0.5 O-1 -0.5 0.5 0.5 1 1 1.5 1.5 2 2(c) Repeat part (a) using a midpoints. M3 = 14 M6 = 20.95 X Sketch the curve and the approximationg rectangles for M3. 15 - 15 15 15 10 10 10 10 5 5 O-1 O- 2 2 10-1 2 Sketch the curve and the approximationg rectangles for M6- 15 15 15 15 10 10 10 10 O-1 -0.5 0.5 1 1.5 2 O- 0.5 0.5 1.5 2 10-1 .0.5 0.5 1 1.5 2 -0.5 0.5 1 1.5 2 (d) From your sketches in parts (a)-(c), which estimate appears to be the most accurate? OMG OR6