Question

The function $f$ : $A\to B$ defined by $f(x)=4x+7$, $x\in R$ is

• A. one-one
• B. Many-one
• C. Odd
• D. Even

Answer 1

Answer: (A)

We hawe, $f(x)=4x+7$, $x\in R$
Let $x_1$, $x_2\in R$, such that $f(x_1)=f(x_2)$
$\Rightarrow 4x_1+7=4x_2+7$
$\Rightarrow 4x_1=4x_2$
$\Rightarrow x_1=x_2$
So, $f$ is one - one.