Practicing Success
If $2f(x)-3f(1/x)=x^2$, x is not equal to zero, then f(2) is equal to |
$\frac{5}{2}$ $-\frac{7}{4}$ -1 none of these |
$-\frac{7}{4}$ |
$2f(x)-3f(\frac{1}{x})=x^2$ ...(1) so as $x→\frac{1}{x}$ $2f(\frac{1}{x})-3f(x)=\frac{1}{x^2}$ ...(2) eq. (1) × 2 + eq. (2) × 3 $4f(x)-6f(\frac{1}{x})=2x^2 + 6f(\frac{1}{x})-9f(x)=\frac{3}{x^2}$ $-5f(x)=2x^2+\frac{3}{x^2}$ at $x=2$ $⇒-5f(2)=8+\frac{3}{4}⇒-\frac{7}{4}$ |