If x = a sec θ and y = b tan θ, then b2x2 a2y2 =

Given: x = a sec θ and y = b tan θ

x2 = a2 sec2 θ and y2 = b2 tan2 θ ……………………(i)


To find: b2x2 – a2y2


Consider b2x2 – a2y2 = b2 a2 sec2 θ – a2 b2 tan2 θ


= a2 b2 (sec2 θ – tan2 θ)


= a2 b2 (1) [ sec2 θ – tan2 θ = 1]


= a2 b2

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