31.10.2014 Views

A history of Greek mathematics - Wilbourhall.org

A history of Greek mathematics - Wilbourhall.org

A history of Greek mathematics - Wilbourhall.org

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

ON THE SPHERE AND CYLINDER, II 47<br />

(iii) Solution <strong>of</strong> the original problem <strong>of</strong> II. 4 by Diocles.<br />

Diodes proceeded in a different manner, satisfying, by<br />

a geometrical construction, not the derivative cubic equation,<br />

but the three simultaneous relations which hold in Archimedes's<br />

proposition, namely<br />

HM:H'M = m:n<br />

HA: h = r :h'<br />

H'A'\ I! = r:hj<br />

with the slight generalization that he substitutes for r in<br />

these equations another length a.<br />

The problem is, given a straight line A A', sl ratio m :<br />

AK (= a), to divide A A' at a point M<br />

n, and<br />

another straight line<br />

and at the same time to find two points H, ffl on A A'<br />

produced such that the above relations (with a in place<br />

<strong>of</strong> r) hold.<br />

The analysis leading to the construction is very ingenious.<br />

Place AK (= a) at right angles to AA', and draw A'K' equal<br />

and parallel to it.<br />

Suppose the problem solved, and the points M, H, Hf<br />

found.<br />

Join KM, produce it, and complete the rectangle KGEK f .<br />

all

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!