

m 



// / If J 



i IM-UI il IMIIHI I..- {.rttiiied / 



ug, keeping it 

 taut \\h. 

 muved along the directrix, aa 



tt-l in thr figure, then, __/ 

 very position of P, 



// 



will trace 



arabola. 





135. The equation of the tangent to the parabola y* = 4jN0 



in terms of its slope. Tin- lim- h.i\in^ tin- 



y = mj + ki . (1) 



it is ilrMiv.l in lin.l that value nf k fur whirh this lint- will 

 become tangent to tin- iaral>ola whoso equation i> 



^=^ (2) 



i.-niiir M|uati.-:,- ( 1 i Uld < - iml 



flin. <-|iiatiuii. whirh 



has for ita rooto the abeciasas <>f th<- t\\u points in whuh the 



[Uatiul; - JitrrstM-I i Will 



become - ' ), ami thnvfuiv th,- J M , 



'ii \\ill liecome Coincident, it' 



i..., if kZ; . (4) 



re v = mjr ^ . . [66] 



ill values of IN, thr jii.it i. !! of a tangent to the 



na 



-4j 



