Q. The function $f:C \rightarrow C$ defined by $f(x) = \frac{ax + b}{cx + d}$ for $x \in C$ where $bd \neq 0$ reduces to a constant function, if

A) $a = c$
B) $b = d$
C) $ad = bc$
D) $ab = cd$
Explanation

(c)
Given, $f(x) = \frac{ax + b}{cx + d}$
It reduces the constant function if
$\ \ \ \ \ \ \ \ \ \ \frac{a}{c} = \frac{b}{d}\ \Rightarrow \ \ \ ad = bc$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.