UPSEE Solved Model Paper 4

3 f(x) + b f(1/x) = x ... (i)
substituting 1/x in place of x
3 f(1/x) + b f(x) = 1/x ... (ii)
Above is a system of equation in f (x) and f(1/x)
Operating (i) × 3 - (ii) × b
(9−b2)f(x) = 3x -

b

x

f(x) =

3x2−b

x(9−b2)

But f 92) = 0
0 =

(12−b)

2(9−b2)

b = 12