Use the comparison test to determine whether the series is convergent or divergent
Answer:
b) diverges
Step-by-step explanation:
Given is a series with the terms
[tex]\frac{25}{3} +\frac{125}{9} +\frac{625}{27} +...[/tex]
We find that this series follows a pattern such that each term is multiplied by 5/3 to get the next term.
In other words, this is a geometric series with I term=25/3 and common ratio=5/3
Sum of geometric series upto n terms
=[tex]\frac{a(r^n-1}{r-1} =\frac{25}{3} (\frac{(\frac{5}{3} )^n-1}{\frac{5}{3}-1 } )\\[/tex]
Since r>1, we find that this series diverges to infinity
Hence answer is
B) divergent
Answer:
Series is divergent .
Step-by-step explanation:
Here nth term of the given series is
[tex]\frac{5^{n+1} }{3^n}[/tex]
Let the given series be [tex]a_{n} =[/tex][tex]\frac{5^{n+1} }{3^n}[/tex]
Let [tex]b_{n} =[/tex] = [tex]\frac{5^{n} }{3^n}[/tex]
[tex]\lim_{n \to \infty} \frac{a_n}{b_n} \\ \lim_{n \to \infty} \frac{\frac{5^(n+1)}{3^n} }{\frac{5^n}{3^n} }[/tex]
on simplifying it ,we get
limit of the ratio = 5 (which is finite and nonzero)
therefore using comparison test both an and bn converge or diverge together .
for bn = [tex]\frac{5^{n} }{3^n}[/tex] is a geometric series with
common ratio [tex]\frac{5}{3}[/tex] >1
therefore for bn series is divergent.
therefore an also divergent ( using comparison test)