Discorsi Propositions 3/06-pr-03 Discorsi Proposition3/06-pr-03

 PROPOSITIO VI, PROBLEMA. PROPOSITION VI, PROBLEM Data sublimitate et altitudine semiparabolae, amplitudinem reperire. Given the sublimity and the altitude of a parabola, to find its amplitude. Sit ad horizontalem lineam dc perpendicularis ac, in aqua data sit altitudo {10} cb et sublimitas ba: oportet, in horizontali cd amplitudinem semiparabolae reperire, quae ex suplimitate ba cum altitudine bc designatur.Accipiatur media proportionalis inter cb, ba, cuius cd ponatur dupla: dico, cd esse amplitudinem quaesitam.Id autem ex praecedenti manifestum est. Let the line ac in which lie the given altitude cb and sublimity ab, be perpendicular to the horizontal line cd. The problem is to find the amplitude, along the horizontal cd, of the semi-parabola which is described with the sublimity ba and altitude bc. Lay off cd equal to twice the mean proportional between cb and ba. (Condition 3/05-pr-02-cor) Then cd will be the amplitude sought, as is evident from the preceding proposition.

 Discorsi Propositions 3/06-pr-03 Discorsi Proposition3/06-pr-03