Purchase Solution

First five positive deficient square pentagonal numbers

Not what you're looking for?

Ask Custom Question

The m-th number is the number Pm = 1/2 m (3m - 1 ).
A pentagonal number is a deficient square if Pm = n^2 - 1 for some integer n.
Find the first five positive deficient square pentagonal numbers.

The answer should demonstrate in a table with 3 columns how to get the corresponding m, n and Pm for each of the 5 numbers.

Purchase this Solution

Solution Summary

In this solution we use a modified version of Pell's equation to find the first five deficient square pentagonal numbers.

Solution Preview

** Please see the attachment for the complete solution **

We wish to find the first five positive deficient square pentagonal numbers. This amounts to finding the five smallest positive integer solutions to the Diophantine equation
(please see the attached file)

which we may write as:
(please see the attached file)

Multiplying both sides by 24, we obtain:
(please see the attached file)

Adding 1 to both sides yields:
(please see the attached file)

whence:
(please see the attached file)

This is a Pell-like equation, which we know how to solve. Let (please see the attached file) and (please see the attached file). Then we have:
(please see the attached file)
(1)

By inspection, we see that (please see the attached file) is a solution ...

Purchase this Solution


Free BrainMass Quizzes
Geometry - Real Life Application Problems

Understanding of how geometry applies to in real-world contexts

Exponential Expressions

In this quiz, you will have a chance to practice basic terminology of exponential expressions and how to evaluate them.

Probability Quiz

Some questions on probability

Know Your Linear Equations

Each question is a choice-summary multiple choice question that will present you with a linear equation and then make 4 statements about that equation. You must determine which of the 4 statements are true (if any) in regards to the equation.

Graphs and Functions

This quiz helps you easily identify a function and test your understanding of ranges, domains , function inverses and transformations.