Question

If the domain of the function $f(x)=x^2-6x+7$ is $(-\infty ,\infty )$, then the range of function is

• A. $(-\infty ,\infty )$
• B. $[-2,\infty )$
• C. $(-2,3)$
• D. $(-\infty ,-2)$

Answer 1

Answer: (B)

Now, $x^2-6x+7=(x-3{)}^2-2$
It is obvious that minimum value is $-2$ and maximum value is $\infty$.