Question

$A=\{-1,0,1,2\},B=\{2,3,6\}$. If $f\left(x\right)$ from $A$ into $B$ is defined by $f\left(x\right)=x^2+2$, then $f$ is

• A. a function
• B. one-one
• C. into
• D. one-one and onto

Answer 1

The correct option is A a function

$f\left(x\right)=x^2+2$
$f(-1)=3$
$f\left(0\right)=2$
$f\left(1\right)=3$
$f\left(2\right)=6$
$\because$ Range of $f\left(x\right)$ lies in its codomain
$\therefore$ $f\left(x\right)$ is a function.