Examine the integral . Homework Help ✎

1. Explain why this integral cannot be evaluated exactly using any of our integration tools.

2. Estimate , using a Riemann sum with 5 left-endpoint rectangles.

3. Use a substitution in the expansion of f(x) = e^x to get a 6^th degree polynomial approximation of .

4. Estimate using the polynomial of part (c).

5. How could we have improved our answers to parts (b) and (d)?