Conics question (Reflective property) (1 Viewer)

[Hermes1]

question 4 (a) (iv) of this trial paper:

http://www.angelfire.com/ab7/fourunit/knox2010.pdf

i did the first part. how do u then use this to prove the normal PN bisects the angle.

 

[funnytomato]

PS/PS'=NS/NS'

using sine rule
sin(PNS)/sin(PNS')=sin(NPS)/sin(NPS')

but PNS = 180 - PNS'
sin(PNS)=sin(PNS'), ASTC

sin(NPS)/sin(NPS')=sin(PNS)/sin(PNS')=1
sin(NPS)=sin(NPS')
Then it follows that NPS=NPS'

(you could also produce similar triangles to prove it)

 

[Hermes1]

tnks man.