Methodus inveniendi lineas curvas

262 DE CURVIS qua laminæ extremitates A, B ad se invicem contrahi debent; erit $= \frac{Ekk}{ff} \times \frac{\pi a a}{2}$. Propius vero reperitur $f = \frac{\pi a}{2\sqrt{2}} \times 1,1803206$, hincque $b = \frac{\pi a a}{4f} = \frac{a}{\sqrt{2}} \times 1,1803206$; unde in numeris puris erit $\frac{f}{a} = 1,311006$, & $\frac{b}{a} = 0,834612$. 28. Si $c > a$, orietur species quarta, eousque patens, quoad fiat $AD = b = 0$; qui alter limes ipsius $c$ definietur per hanc æquationem: $x = \frac{1}{2} x \times \frac{cc}{2aa} + \frac{1^2 \cdot 3^2}{2^2 \cdot 4^2} \times \frac{c^4}{4a^4} + \frac{1^2 \cdot 3^2 \cdot 5^2}{2^2 \cdot 4^2 \cdot 6^2} \times \frac{c^6}{ [TRUNCATED]