### Home > PC > Chapter 6 > Lesson 6.1.1 > Problem 6-13

6-13.

Consider the function

*f*(*x*) = −( *x*− 1)^{2}+ 7 for 1 ≤*x*≤ 4. Homework Help ✎Write the sum to find the area under the curve using left-hand endpoints and rectangles with widths of 1. Since you are not using a calculator, be sure you set up your sum to include *all*of the factors. You do*not*need to actually calculate the sum.Write the sum using sigma notation.

*f*(1) + *f*(2) + *f*(3)