To solve the problem, we can use the method of completing the square, which is efficient for analyzing quadratic functions.
Step 1: Prove (f(x) = x^2 - 2x + 3) is always positive
Complete the square for the quadratic term:
[
\begin{align}
f(x) &= x^2 - 2x + 3 \
&= (x^2 - 2x + 1) + 2 \quad \text{(add and subtract 1 to complete the square)} \
&= (x - 1)^2 + 2.
\end{align}
]
Since ((x - 1)^2 \geq 0) for all real (x), adding 2 gives:
[
f(x) = (x - 1)^2 + 2 \geq 2 > 0.
]
Thus, (f(x)) is always positive.
Step 2: Find the minimum value of (f(x))
From the vertex form ((x - 1)^2 + 2):
- The term ((x - 1)^2) reaches its minimum value of 0 when (x = 1).
- Substituting (x = 1) into (f(x)):
[ f(1) = (1 - 1)^2 + 2 = 2. ]
Final Answers:
- (f(x)) is always positive because it equals ((x-1)^2 + 2 \geq 2 > 0).
- The minimum value of (f(x)) is (\boxed{2}).
(\boxed{2})


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