Please help!!! By completing the square in x^2-2x+3, find the minimum value of f(x)=x^2-2x+3
Do you really need to complete the square just to find the minimum value?
yeah .
Why not just simply use the vertex formula?
I'm not finding the vertex.
You're finding the minimum value of the function. To do that, use the formula for x coordinate of the vertex: \[x = -\frac{b}{2a}\]
Then plug that value for x into the function, then find y coordinate.
can you show me, I don't understand,
\[x = -\frac{-2}{2(1)} = 1 \\y = f(x) \\y = x^2 -2x + 3 \\y = (1)^2 - 2(1) + 3 \\y = 1 - 2 + 3 \\ y = 3 + 1 - 2 \\ y = 4 - 2 \\y = 2\]
Thus the minimum point is (1,2)
Ohhhhh!! Thank Youu!!
I hope you understand how to do these now.
Completing the square: f(x) = x^2-2x+3 = (x-1)^2-1+3 = (x-1)^2+2. You can now see that this expression is minimal at x=1. The minimum is f(1) = 2.
I was just showing her how to do it the easy way first.
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