Answers

2014-06-10T16:22:17+05:30
X² - y² = a² and xy= c²
2x - 2ydy/dx = 0
dy/dx = x/y  = m1
xy = c²
y + xdy/dx = 0
dy/dx = -y/x   m2
if they cut orthogonally then there tangent also cut orthogonally 
for two line cut orthogonally m1*m2 = -1
(x/y)(-y/x) = -1
hence they cut orthogonally . 
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