Function given: F(b) = ∫e-x2dx from 0 to b I'm asked to estimate F(1), F(2), and F(3) using a left-sum with 3 subdivisions. So, I guess Δx would be 1, then, so it doesn't really matter for the purposes of solving this problem. However, this is as far as I've gotten, and I haven't really been able to make much progress. Can anyone suggest another step I can take to come closer to the solution? Thank you!