Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

If $af(x)+bf(\frac{1}{x})=x-1$, x ≠ 0 and a ≠ b, then f(2) =

Options:

$\frac{a}{a^2-b^2}$

$\frac{a+2b}{a^2-b^2}$

$\frac{a-2b}{a^2-b^2}$

none of these

Correct Answer:

none of these

Explanation:

Given, $af(x)+bf(\frac{1}{x})=x-1, x ≠ 0, a ≠ b$  …(i)

$⇒af(\frac{1}{x})+bf(x)=\frac{1}{x}-1$   …(ii)

a . (i) − b . (ii)

$⇒ (a^2 − b^2) f(x) = a(x-1)-b(\frac{1}{x}-1)⇒(a^2 − b^2) f(2)=a+\frac{b}{2}=\frac{2a+b}{2}$

$⇒f(2)=\frac{2a+b}{2(a^2-b^2)}$