Functions Question 431
Question: Let $ f(x)=x,g(x)=\frac{1}{x} $ and $ h(x)=f(x)g(x). $ Then, $ h(x)=1 $ if and only if
Options:
A) x is a real number
B) x is a rational number
C) x is an irrational number
D) x is a non-zero real number
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ D(f)=R,D(g)=R-{0} $
$ \therefore D(h)=R-{0} $ and $ h(x)=f(x)g(x)=x\times \frac{1}{x}=1 $
$ \therefore h(x)=1 $ if and only if $ x\in R-{0} $
BETA
