You should recognize this Riemann sum as the Definition of an Integral.
Thus, your job is to connect the given Riemann sum to the parts of an integral:
Start by answering these questions: What represents
You probably want to factor out the 2
What represents the integrand,
In order to identify the
Look for the part of the series that is changing: the numerators!
The first numerator is
Now each variable is being divided by
because we are evaluating values
What are the bounds?
The bounds are the smallest input and the largest input into the variable.
Since the integrand is
Let's look at the smallest and largest value of
The smallest value of
The largest value of
So the bounds are form