The Diophantine Equation x2 + Dy2 = z2 (Part I)

A Method of Generating Triples from Novel Equations

A new, general method for generating triples of the form (x,y,z) for the Diophantine equation x2 + Dy2 = z2, where D, is any integer greater than zero. The method produces a set of novel second order equations which generates Diophantine triples. These equations are listed below using the following table heading format:

δ1x y z δ2
a Da2 - n2 2na Da2 + n2

where a is a generating number starting at zero, D is any integer greater than zero and (n2, 2n) are values taken from table A:

Table A (n2 & 2n values)
n2149162536496481100...
2n2468101214161820...

Since there are an infinite number of (n2, 2n) integers there are also an infinite number of tables which can be tabulated with their accompanying equations. A second sequential access is also possible using the δ1 and δ2 columns whose δ1δ1 and δ2δ2 are both 2 for all the tables. In addition,the triples which are generated may be present in primitive or non primitive form, and these non primitives can be converted to primitive forms by dividing out any common factors. When D equals one the Diophantine equation takes the form of x2 + y2 = z2 also known as the Pythagorean equation. This section can be compared to a known method for generating Pythagorean triples in Part IC applicable only to the Pythagorean and not to the general series of Diophantine equations in Parts II thru VIII.

Table I
δ1x y z δ2
a a2 - 1 2a a2 + 1
0-101
11
1022
33
2345
55
38610
77
415817
99
5241026
1111
6351237
1313
7481450
Table II
δ1x y z δ2
a a2 - 4 4a a2 + 4
0-404
11
1-345
33
2088
55
351213
77
4121620
99
5212029
1111
6322440
1313
7452853

Next comes Tables III and IV.

Table III
δ1x y z δ2
a a2 - 9 6a a2 + 9
0-909
11
1-8610
33
2-51213
55
301818
77
472425
99
5163034
1111
6273645
1313
7404258
Table IV
δ1x y z δ2
a a2 - 16 8a a2 + 16
0-16016
11
1-15817
33
2-121620
55
3-72425
77
403232
99
594041
1111
6204852
1313
7335665

Next comes Tables V and VI.

Table V
δ1x y z δ2
a a2 - 25 10a a2 + 25
0-25025
11
1-241026
33
2-212029
55
3-163034
77
4-94041
99
505050
1111
6116061
1313
7247074
Table VI
δ1x y z δ2
a a2 - 36 12a a2 + 36
0-36036
11
1-351237
33
2-322440
55
3-273645
77
4-204852
99
5-116061
1111
607272
1313
7138485

Finally we have Tables VII and VIII.

Table VII
δ1x y z δ2
a a2 - 49 14a a2 + 49
0-49049
11
1-481450
33
2-452853
55
3-404258
77
4-335665
99
5-247074
1111
6-138485
1313
709898
Table VIII
δ1x y z δ2
a a2 - 64 16a a2 + 64
0-64064
11
1-631665
33
2-603268
55
3-554873
77
4-486480
99
5-398089
1111
6-2896100
1313
7-15112113

Only eight triples, (x,y,z), were used in the calculation for the Diophantine equation x2 + y2 = z2 , normally known as the Pythagorean equation, to get an idea of its versatility. Note that the tables produced can be expanded downward indefinitely. In addition, using the tables one can generate the appropriate equations that are useful for generating any triple in a table using a random access method or using δ1 and δ2 to access the (x,y,z)s sequentially.

This concludes Part I. Go to Part II or Part IC.

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Copyright © 2020 by Eddie N Gutierrez. E-Mail: enaguti1949@gmail.com