The Total solution for NCERT class 6-12
Given:
y = f (x) = (ax – b) / (bx – a) ⇒ f (y) = (ay – b) / (by – a)
Let us prove that x = f (y).
We have,
y = (ax – b) / (bx – a)
By cross-multiplying,
y(bx – a) = ax – b
bxy – ay = ax – b
bxy – ax = ay – b
x(by – a) = ay – b
x = (ay – b) / (by – a) = f (y)
∴ x= f (y)
Hence proved.