foctu of a parabola, and the 

 fixed strai Ox pan through the , then 



latuM rectum of the parabola. 



a ; 



[ eo0 , a fctnf iff -tin* 10 



iow Jc^i/ tf -J -Si*- - 



-/(I -Un'Jtf) (1 + Un* 



fore < - 8 (tn J/9-t*n i) - 1 (tw'l/9-Un'l) 



AUo f ./(l+tan Jtf) sec- 1<?^ = 2 tM JO+ tan' JO 

 :bre 



fowi-l. ~ tan 



tan'la) 



sn 



tore 



