find two consecutive odd positive integers sum of whose square is 290

5 hours ago 4
Nature

Let's solve the problem step-by-step.

Problem:

Find two consecutive odd positive integers such that the sum of their squares is 290.

Step 1: Define variables

Let the first odd positive integer be xxx.
Since the integers are consecutive odd numbers, the next consecutive odd integer will be x+2x+2x+2.

Step 2: Write the equation

The sum of their squares is given as 290:

x2+(x+2)2=290x^2+(x+2)^2=290x2+(x+2)2=290

Step 3: Expand and simplify

x2+(x2+4x+4)=290x^2+(x^2+4x+4)=290x2+(x2+4x+4)=290

2x2+4x+4=2902x^2+4x+4=2902x2+4x+4=290

2x2+4x+4−290=02x^2+4x+4-290=02x2+4x+4−290=0

2x2+4x−286=02x^2+4x-286=02x2+4x−286=0

Divide the entire equation by 2 to simplify:

x2+2x−143=0x^2+2x-143=0x2+2x−143=0

Step 4: Solve the quadratic equation

Use the quadratic formula x=−b±b2−4ac2ax=\frac{-b\pm \sqrt{b^2-4ac}}{2a}x=2a−b±b2−4ac​​, where a=1a=1a=1, b=2b=2b=2, and c=−143c=-143c=−143:

x=−2±22−4×1×(−143)2×1x=\frac{-2\pm \sqrt{2^2-4\times 1\times (-143)}}{2\times 1}x=2×1−2±22−4×1×(−143)​​

x=−2±4+5722x=\frac{-2\pm \sqrt{4+572}}{2}x=2−2±4+572​​

x=−2±5762x=\frac{-2\pm \sqrt{576}}{2}x=2−2±576​​

x=−2±242x=\frac{-2\pm 24}{2}x=2−2±24​

Two possible solutions:

  1. x=−2+242=222=11x=\frac{-2+24}{2}=\frac{22}{2}=11x=2−2+24​=222​=11
  2. x=−2−242=−262=−13x=\frac{-2-24}{2}=\frac{-26}{2}=-13x=2−2−24​=2−26​=−13

Since the problem states positive integers, we take x=11x=11x=11.

Step 5: Find the consecutive odd integer

The next consecutive odd integer is:

x+2=11+2=13x+2=11+2=13x+2=11+2=13

Step 6: Verify the solution

112+132=121+169=29011^2+13^2=121+169=290112+132=121+169=290

This matches the given condition.

Final Answer:

The two consecutive odd positive integers are 11 and 13.