- Home
- Standard 12
- Mathematics
1.Relation and Function
easy
माना फलन $f$ इस प्रकार परिभाषित है कि $f(x) = \frac{{2x + 1}}{{1 - 3x}}$, तब ${f^{ - 1}}(x) =$
A
$\frac{{x - 1}}{{3x + 2}}$
B
$\frac{{3x + 2}}{{x - 1}}$
C
$\frac{{x + 1}}{{3x - 2}}$
D
$\frac{{2x + 1}}{{1 - 3x}}$
Solution
(a) माना $y = f(x)$ ==> $y = \frac{{2x + 1}}{{1 – 3x}}$ ==> $y – 3xy = 2x + 1$
==> $x = \frac{{y – 1}}{{3y + 2}}$ ==> ${f^{ – 1}}(y) = \frac{{y – 1}}{{3y + 2}} $
$\Rightarrow {f^{ – 1}}(x) = \frac{{x – 1}}{{3x + 2}}$.
Standard 12
Mathematics