### Home > PC > Chapter 2 > Lesson 2.3.6 > Problem2-150

2-150.

Represent the following expression using summation notation.

$0.5 \sqrt { 2 } + 0.5 \sqrt { 2.5 } + 0.5 \sqrt { 3 } + \ldots 0.5 \sqrt { 12 }$

Since all of the terms have a 0.5 multiplier, factor that out.

$0.5\displaystyle\sum$

How many terms are there?

$21$

Decide if you will start at $0$ or start at $1$.

$\displaystyle\sum\limits_{k=0}^{20}0.5\sqrt{0.5\textit{k}+2}$

$\displaystyle\sum\limits_{k=1}^{21}0.5\sqrt{0.5\textit{k}+1.5}$