I understand how to do it's just I don't understand what a certain part of my homewor kmeans.

What does f(u) mean? I plug in u for the values of x?Using the method of u-substitution,

where

(enter a function of x)

dx (enter a function of x)

(enter a number)

(enter a number)

(enter a function of u).

The value of the original integral is .