A sequence is defined by the recurrence relation u(n+1) = 1/3 u(n) + 10 with u(3) = 6 . Find the value of u(4) and the limit of the sequence.

A sequence is defined by the recurrence relation un+1 = 1/3 un + 10  with u3 = 6 . Find the value of u4 and the limit of the sequence.

To find the value of u4 we replace un by u3 in the equation and then calculate un+1

u4 = 1/3 u3 + 10

u4 = 1/3 x 6 + 10

u4 = 2 + 10

u4 = 12

To find the limit of the series we have to find for which value un+1 is equal to un .

Let's call this value x . Then we have:

x = 1/3 x + 10

We can subtract 1/3 x on both sides to get:

x - 1/3 x = 10

2/3 x = 10

Now we multiply by 3 and then divide by 2:

x = 10 x 3 / 2

x = 15

The limit of the sequence is 15.

Answered by David-Ruben S. Physics tutor

9075 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

What is the law of conservation of energy?


A note was played on an electric keyboard. The frequency of the note was 440Hz. What does a frequency of 440 Hz mean?


What is the difference between a scalar and a vector quantity?


Why is the sky blue?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences