Question

If $f:A\to A$, then range of $f$ where $A=\{1,2,3,4\}$ and $f\left(x\right)=x^2+x+2$

Answer 1

Given:$f:A\to A$

$f\left(1\right)=1^2+1+2=1+1+2=4$

$f\left(2\right)=2^2+2+2=4+2+2=8$

$f\left(3\right)=3^2+3+2=9+3+2=14$

$f\left(4\right)=4^2+4+2=16+4+2=22$

$\therefore$ Range of $A=\{4,8,14,22\}$