Hi all,

I need a little help with this summation problem.

Find the value of,

$\displaystyle \sum_{r=1}^4 a_r$

For, $\displaystyle a_r = 2 + \sqrt r$

I tried to solve it like this,

$\displaystyle = 2(4) + \sum_{r=1}^4 \sqrt r$

What is the series,

$\displaystyle 1, \sqrt 2, \sqrt 3, \sqrt 4, + ...$.

Its clearly not a A.P. It also doesn't seem like a G.P. How do I calculate the sum of such a series?

Thanks for your help.

P.S. Latex doesn't work anymore. I used QuickLatex to explain the problem.