Chapter 13 - A Preview of Calculus: The Limit, Derivative, and Integral of a Function - Section 13.5 The Area Problem; The Integral - 13.5 Assess Your Understanding - Page 923: 8

$$38$$

Our aim is to calculate the approximation of $A$, the area under the function using the right endpoints. Therefore, we have: $$A=(2-0)f(2)+(4-2)f(4)+(6-4)f(6)+(8-6)f(8)\\=2f(2)+2f(4)+2f(6)+2f(8)\\=2[6+7+5+1] \\=(2)(19) \\ =38$$