The range of function f(x) = x2 - 2x + 2; x ∈ R is:
Answer & explanation
Correct answer: option 1
Given
$f(x)=x^2-2x+2$
Complete the square
$f(x)=x^2-2x+1+1$
$f(x)=(x-1)^2+1$
Since $(x-1)^2 \ge 0$ for all $x \in \mathbb{R}$
Minimum value occurs when
$(x-1)^2=0$
$x=1$
$f(1)=1$
Thus
$f(x)\ge1$
The range is $[1,\infty)$.