Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

If $f(x)+2f(1-x)=x^2+2,∀\,x∈R$, then f(x) is given as

Options:

$\frac{(x-2)^2}{3}$

$x^2-2$

1

none of these

Correct Answer:

$\frac{(x-2)^2}{3}$

Explanation:

$f(x)+2f(1-x)=x^2+2$ …(i)

Replacing x by 1 – x in (i), we get ⇒ $f(1-x)+2f(x)=(1-x)^2+2$

$⇒ f(1-x)+2f(x)=x^2-2x+3$ …(ii)

Eliminating f(1− x) from (i) and (ii), $f(x)=\frac{(x-2)^2}{3}$