Approximating area under curve

Practice: Area using Riemann Sums

The area bounded by the function f(x)f\left(x\right) and the xx-axis in the interval [a, b]\left[a,\ b\right] is represented by limn i=1n(3n)[cos(2+3in)(2+3in)]\displaystyle \lim_{n\rightarrow\infty}\ \sum_{i=1}^n\left(\frac{3}{n}\right)\left[\frac{\cos\left(2+\frac{3i}{n}\right)}{\left(2+\frac{3i}{n}\right)}\right].
Find the function f(x)f\left(x\right) and the interval [a, b]\left[a,\ b\right].

More Approximating Areas & Riemann Sums Questions: