The following sum

\sqrt{9 - \left(\frac{3}{n}\right)^2} \cdot \frac{3}{n} +
\sqrt{9 - \left(\frac{6}{n}\right)^2} \cdot \frac{3}{n} +
\ldots + \sqrt{9 - \left(\frac{3 n}{n}\right)^2} \cdot \frac{3}{n}

is a right Riemann sum for the definite integral\int_0^b f(x)\, dx
where b =

andf(x) =

is a right Riemann sum for the definite integral

and

The limit of these Riemann sums as

You can earn partial credit on this problem.