Please fast 7 . I f tan α tan β = - a 2 b 2 , t h e n t h e c h o r d j o i n i n g t w o p o i n t s α a n d β o n t h e e l l i p s e x 2 a 2 + y 2 b 2 = 1 w i l l s u b t e n d a r i g h t a n g l e a t ( a ) f o c u s ( b ) c e n t r e ( c ) e n d o f m a j o r a x i s ( d ) e n d o f m i n o r a x i s Share with your friends Share 0 Aarushi Mishra answered this Consider, two points Aα and BβA=a cos α, b sin α B=a cos β, b sin β Let O be the origionThen slope of OA, m1=b sin αa cos α=batan αThen slope of OB, m2=b sin βa cos β=batan βm1.m2=batan αbatan βm1.m2=b2a2tan α tan βGiven:tan α tan β=-a2b2m1.m2=b2a2-a2b2=-1Thus angle between OA and OB is 90°Therefore chord AB subtends right angle at origion 0 View Full Answer