Question

If $A=\{1,2,3,4\},B=\{1,2,3,4,\mathrm{5....25}\}$ and $f:A\to B$ is a function such that $f\left(x\right)=x^2,$ then the number of elements in the range of $f\left(x\right)$ is

Answer 1

$\because f\left(x\right)=x^2$ and $f:A\to B$
$\therefore$ range is
$f\left(A\right)=\{1,4,9,16\}$
Hence required number of element $=4$