A A13235378 New member Joined Sep 1, 2020 Messages 3 Sep 10, 2020 #1 A sequence {an} of real numbers is defined by: [MATH]a_1=1,a_{n+1}=1+a_1.a_2.a_3...a_n,n\geq 1 [/MATH] prove that : [MATH]\sum_{n=1}^{\infty }\frac{1}{a_n}=1 [/MATH]
A sequence {an} of real numbers is defined by: [MATH]a_1=1,a_{n+1}=1+a_1.a_2.a_3...a_n,n\geq 1 [/MATH] prove that : [MATH]\sum_{n=1}^{\infty }\frac{1}{a_n}=1 [/MATH]
tkhunny Moderator Staff member Joined Apr 12, 2005 Messages 11,337 Sep 10, 2020 #2 Can you write out the first three terms?
D Deleted member 4993 Guest Sep 10, 2020 #3 A13235378 said: A sequence {an} of real numbers is defined by: [MATH]a_1=1,a_{n+1}=1+a_1.a_2.a_3...a_n,n\geq 1 [/MATH] prove that : [MATH]\sum_{n=1}^{\infty }\frac{1}{a_n}=1 [/MATH] Click to expand... If I were to do this problem, I would attempt to use method of induction. Please show us what you have tried and exactly where you are stuck. Please follow the rules of posting in this forum, as enunciated at: https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520 Please share your work/thoughts about this problem.
A13235378 said: A sequence {an} of real numbers is defined by: [MATH]a_1=1,a_{n+1}=1+a_1.a_2.a_3...a_n,n\geq 1 [/MATH] prove that : [MATH]\sum_{n=1}^{\infty }\frac{1}{a_n}=1 [/MATH] Click to expand... If I were to do this problem, I would attempt to use method of induction. Please show us what you have tried and exactly where you are stuck. Please follow the rules of posting in this forum, as enunciated at: https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520 Please share your work/thoughts about this problem.