Answer:
Here is the full question:
Find the sum of the convergent series by using a well-known function. (Round your answer to four decimal places.) Σ_(n=1)^∞ (-1)^n+1 1/7^n n
Step-by-step explanation:
Σ_(n=1)^∞ (-1)^n+1 1/7^n n
We will use the function In (1 + x)
We will now give a power series expansion of the function while it is centered at x=0
This will give us In (1 + x) = Σ_(n=1)^∞[tex](-1)^{n+1}[/tex][tex]\frac{x^{n} }{n}[/tex]
Note that x= 1/7
Now let us equate the two equations
Σ_(n=1)^∞[tex](-1)^{n+1}[/tex][tex]\frac{1}{7^{n}n }[/tex] = ㏑(1 + x)|[tex]_{x = \frac{1}{7} }[/tex] = ㏑[tex]\frac{8}{7}[/tex]
Sum of the series will give ㏑[tex]\frac{8}{7}[/tex]
