what I understood from Baz's post

what Christenson wrote

Let us look at Christenson's equation without the points

Break this into two integrals

Let us do the harder integral first

A is a constant and can be placed outside of the integral

Next is an u-substitution

let

then

Therefore

Substitute the values

Again since

is a constant move it out of the integral

Now you have

Which is

replace the u for what was substituted

Now do the second integral

The whole equation is

Evaluating from a to b i.e.

it would be the following

Entering in all the values =6.25624