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A history of Greek mathematics - Wilbourhall.org

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514 DIOPHANTUS OF ALEXANDRIA<br />

term in the first). Diophantus takes p = 64, making<br />

the equations<br />

m 2 — 61 44 m + 1048576 = a square]<br />

m + 64 = a square)<br />

Multiplying the second by 16384, and subtracting the two<br />

expressions, we have as the difference m 2 — 22528m.<br />

Diophantus observes that, if we take m, m— 22528 as<br />

the factors, we obtain m = 7680, an impossible value for<br />

the area <strong>of</strong> a right-angled triangle <strong>of</strong> perimeter <br />

VI. 24. z = u +<br />

u, x = v 3 — v, y = w*.<br />

[VI. 6, 7]. (ixf+%mxy = u 2 .<br />

[VI. 8, 9]. H(x + y)}<br />

2<br />

+ ±mxy = u 2 .<br />

[VI. 10, 11]. {i(z + x)} 2 + ±mxy = u 2 .<br />

[VI. 12.] y + (x—y).%xy = u 2 , x = v 2 . (x > y.)<br />

[VI. 14, 15], u 2 zx — \xy .x(z—x) = v 2 . (u 2 < or > \xy.)<br />

The treatise<br />

on Polygonal Numbers.<br />

The subject <strong>of</strong> Polygonal Numbers on which Diophantus<br />

also wrote is, as we have seen, an old one, going back to the

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