Result A sequence {an} is defined recursively by a₁ = 1, a₂ = 4 and an = Then an = n² for all n € N. 2an-1 -an-2 +2 for n ≥ 3.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

please show the following proof in more detail, I'm especially lost on the highlighted part, thank you in advance.

 

Result
Proof
A sequence {an) is defined recursively by
a₁ = 1, a₂ = 4 and an = 2an-1 — an-2 +2 for n ≥ 3.
Then an = n² for all n € N.
We proceed by induction. Since a₁ = 1 = : 12, the formula holds for n = 1. Assume for
an arbitrary positive integer k that ai i² for every integer i with 1 ≤ i ≤k. We show
=
that ak+1 = (k+ 1)². Since a2 = 4, it follows that ak+1 = (k+ 1)² when k = 1. Thus,
we may assume that k ≥ 2. Hence, k + 1 ≥ 3 and so
ak+1 = 2ak - ak-1 + 2 = 2k² − (k − 1)² + 2
=
= 2k² − (k² − 2k + 1) + 2 = k² + 2k + 1 = (k + 1)².
By the Strong Principle of Mathematical Induction, an = n² for all n € N.
Transcribed Image Text:Result Proof A sequence {an) is defined recursively by a₁ = 1, a₂ = 4 and an = 2an-1 — an-2 +2 for n ≥ 3. Then an = n² for all n € N. We proceed by induction. Since a₁ = 1 = : 12, the formula holds for n = 1. Assume for an arbitrary positive integer k that ai i² for every integer i with 1 ≤ i ≤k. We show = that ak+1 = (k+ 1)². Since a2 = 4, it follows that ak+1 = (k+ 1)² when k = 1. Thus, we may assume that k ≥ 2. Hence, k + 1 ≥ 3 and so ak+1 = 2ak - ak-1 + 2 = 2k² − (k − 1)² + 2 = = 2k² − (k² − 2k + 1) + 2 = k² + 2k + 1 = (k + 1)². By the Strong Principle of Mathematical Induction, an = n² for all n € N.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 6 images

Blurred answer
Similar questions
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,