Math Problem Statement

Find two consecutive positive integers , Sum of whose square is 365

Solution

Let's denote the two consecutive positive integers as nn and n+1n+1.

The sum of their squares is given by:

n2+(n+1)2=365n^2 + (n+1)^2 = 365

Expanding and simplifying the equation:

n2+(n2+2n+1)=365n^2 + (n^2 + 2n + 1) = 365

2n2+2n+1=3652n^2 + 2n + 1 = 365

Subtract 1 from both sides:

2n2+2n=3642n^2 + 2n = 364

Divide the entire equation by 2:

n2+n=182n^2 + n = 182

Now, rearrange the equation:

n2+n182=0n^2 + n - 182 = 0

This is a quadratic equation. We can solve it using the quadratic formula:

n=b±b24ac2an = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

For our equation n2+n182=0n^2 + n - 182 = 0, the coefficients are:

  • a=1a = 1
  • b=1b = 1
  • c=182c = -182

Substituting these values into the quadratic formula:

n=1±12+4×1×1822×1n = \frac{-1 \pm \sqrt{1^2 + 4 \times 1 \times 182}}{2 \times 1}

n=1±1+7282n = \frac{-1 \pm \sqrt{1 + 728}}{2}

n=1±7292n = \frac{-1 \pm \sqrt{729}}{2}

n=1±272n = \frac{-1 \pm 27}{2}

This gives us two solutions:

n=262=13n = \frac{26}{2} = 13

or

n=282=14n = \frac{-28}{2} = -14

Since we are looking for positive integers, n=13n = 13.

Thus, the two consecutive positive integers are 13 and 14.

Let's verify:

132+142=169+196=36513^2 + 14^2 = 169 + 196 = 365

The sum of the squares is indeed 365.

Would you like more details or have any questions?

Here are 5 related questions:

  1. What is the general approach to solving quadratic equations?
  2. Can you find two consecutive even integers whose squares sum up to 340?
  3. How would the problem change if the sum of cubes was required instead of squares?
  4. Can you determine two consecutive negative integers that satisfy the same condition?
  5. How does the discriminant help in determining the nature of the roots?

Tip: When solving quadratic equations, always check if the discriminant is a perfect square for easy factorization.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Number Theory

Formulas

Quadratic formula

Theorems

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Suitable Grade Level

Grades 7-9