Aditya Gupta
Last Activity: 6 Years ago
rational function means a ratio of two polynomials. eg. (3x^3+x-1)/(x^3-7x) is a rational function.
now, we can write the eqn as
(ay+a’)x=root( –acy – y(a’c+ac’) – a’c’).......(1),
but x=p(y)/f(y), p and f being polynomials.
so we conclude that LHS of (1) is a rational function as well. which implies that RHS is a rational function too, which is possible iff –acy – y(a’c+ac’) – a’c’ is a perfect square, or discriminant is zero.
so, (a’c+ac’)^2=4aca’c’
or (a’c-ac’)^2=0
or a’c=ac’
or a/a’=c/c’