1. When creating a left-endpoint Riemann sum on the interval [-77.8, 245] using 48 rectangles, the 6th endpoint used to calculate the height of the approximating rectangle would be

2. When creating a right-endpoint Riemann sum on the interval [72.3, 192.8] using 34 rectangles, the 5th endpoint used to calculate the height of the approximating rectangle would be

3. When creating a right-endpoint Riemann sum on the interval [72.3, 192.8] using 34 rectangles, the 5th endpoint used to calculate the height of the approximating rectangle would be

4. An icosahedron is a Platonic solid with a surface thatconsists of 20 equilateral triangles. By what factor does thesurface area of an icosahedron increase as the side length ofeach triangle doubles from a unit to 2a units, if a = 14.9? Round your answer to three decimal places.

5. Let A be the area under y=e^x and above the x-axis, on [0,a].

Let B be the area under y=e^x and above the x-axis, on [0,b].

B is 4.2 times A.

What is b in terms of a?