If $f:R → R$ is defined by $f(x) =x^2-3x+2$ then $f(f(x))$ is :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → $x^4-6x^3+10x^2-3x$
$f(x) =x^2-3x+2$
so $f(f(x))=(x^2-3x+2)^2-3(x^2-3x+2)+2$
$=x^4+9x^2+4-6x^3-12x+4x^2-3x^2+9x-6+2$
$x^4-6x^3+10x^2-3x$