Question

Fill in the blank summataion notation

Answer 1

we have the sequence

5+9+13+...

we have an arithmetic sequence

a1=5

a2=9

a3=13

a2-a1=9-5=4

a3-a2=13-9=4

the common difference is d=4

the general expression is equal to

`a_n=a_1+d\cdot(n-1)`

we have

a1=5

d=4

substitute

`\begin{gathered} a_n=5+4\cdot(n-1) \\ a_n=4n+1 \end{gathered}`

therefore

the notation is equal to

see the attached figure

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