### Home > CALC > Chapter Ch3 > Lesson 3.2.3 > Problem 3-74

3-74.

General form of a left-endpoint Riemann sum:

Hint for choosing the number of rectangles, *n*: While you want to choose a large value for *n*, be mindful that you will use that value to compute Δ*x*.

Since *b* − *a* = 8, it is recommended (though not necessary) that you choose an *n* that is divisible by 8.

You should have recognized that this function is a semi-circle with center at the origin and radius 4. The exact area can be found with geometry.

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