### Home > PC3 > Chapter 8 > Lesson 8.3.3 > Problem8-128

8-128.

Write each of the following expressions using sigma notation.

1. $\frac { 1 } { 3 } + \frac { 1 } { 3.5 } + \frac { 1 } { 4 } + \frac { 1 } { 4.5 } + \ldots + \frac { 1 } { 9.5 }$

$\displaystyle\sum\limits_{\textit{k}=0}^?\frac{1}{3+(?)\textit{k}}$

1. $\sqrt { 5 } + \sqrt { 8 } + \sqrt { 11 } + \sqrt { 14 } + \ldots + \sqrt { 302 }$

$\displaystyle\sum\limits_{\textit{k}=0}^?\sqrt{5+(?)\textit{k}}$

1. $\cos\left(2\right)+2\cos\left(4\right)+3\cos\left(6\right)+\dots+15\cos\left(30\right)$

Use the same thinking process as (a) and (b) above.