Find the condition on a and b for which two distinct chords of the hyperbola x22a2−y22b2=1 passing through (a, b) are bisected by the line x + y = b.
Let the line x + y = b bisect the chord at P (a, b-a)
∴ equation of chord whose mid-point is P (a,b-a)
xa2a2−y(b−a)2b2=a22a2−(b−a)22b2
Since it passes through (a,b)
∴a2a−(b−a)2b=a22a2−(b−a)22b2a2(1a2−1b2)+a(1b−1a)=0a0,a−11a+1b∴a≠±b