### Home > CALC > Chapter 4 > Lesson 4.2.1 > Problem 4-50

4-50.

Notice that this is a Riemann sum with infinitely many rectangles.

And a Riemann sum with infinitely many rectangles is the Definition of an Integral:

Can you rewrite this as an integral?

The *dx* represents the infinitely small width of each rectangle.

Now lets find the height of each rectangle.

Heights, of course, are represented by a function, *f*(*x*).

But what is *f*(*x*)?

Since *x* is a variable, we will let *x* represent the part of the series that is changing:

We still need to find the bounds of the integral.