Q. 26 - Calculus

Question

Write each of the sums in Exercises 21–28 in sigma notation. Identify $m,n,a_k$ in each problem.  

$9+12+15+18+21+24+27$

Step-by-Step Solution

Answer

The sigma notation is $\sum _{k=3}^{9}3k \mathrm{and} m=3,n=9,a_k=3k$

Step 1. Given Information

The given sum is  $9+12+15+18+21+24+27$

Step 2. Explanation

The sum in sigma notation is written as, 

$$\begin{gathered} 9+12+15+18+21+24+27=\left(3\times 3\right)+\left(3\times 4\right)+\left(3\times 5\right)+\left(3\times 6\right)+\left(3\times 7\right)+\left(3\times 8\right)+\left(3\times 9\right) \\ =\sum _{k=3}^{9}3k \\ where, \\ m=3,n=9,a_k=3k \end{gathered}$$