TO GEOMETRICAL PROBLEMS.
279
then tiie equation will stand thus, a 4 — 2fx 2 _ g :
whence x is found rr V f + %/ J' z +
If, instead of the difference, the sum of the sides had
been given, ip order to tind the ditference, the method
of operation would have been the very same, onl}', in
stead of finding the value of x in terms of«, by means
of the equation .v\t + — 2s z a~x z -p s z a* — 2p z x z — 2cpff 2
+ 2p z a z p C 2c/ra\ that of a must have been found*, in
terms of .r, from the same equation. *
PROBLEM XXIII
Having one leg AB of a right-angled triangle ABC ;
to find the other leg BC, so that the rectangle under their
difference (BC —AB) and the hypothenusc AC, may he
equal to the area of the triangle.
Put ABzra,and BC—t; so shall AC — %/ aa P ;
and =r x—a. s/aa -f xx, by the conditions of the
problem. By squaring both sides O
of this equation we have ga z x* = /
x- — °ax P a z X a a -p xx : in /
which the quantities x and« being /
concerned exactly alike, the solu- /
tion will therefore be brought out /
from the general method for ex- /
tracting the roots^ of these kinds of /
according to which, having di- A B
la 1 a
vided the whole by a z x z , we get — — — 2 P
X ~ + —; which, by making zz—-P —; will be
x a ax
reduced down to ^ — z —: 2 X z, or d — 2z — ^:
y— . X d
whence z is given — l + v But since P —- —z t
I.
T 4
■