9514 1404 393
Answer:
-21
Explanation:
I find it convenient to read the value from the graph created by a graphing calculator. The minimum is -21.
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The function can be rearranged to vertex form, which also shows the minimum value.
g(x) = (x^2 -6x +9) -12 -9*
g(x) = (x -3)^2 -21 . . . . . . . . vertex form
The vertex is (3, -21), so the minimum is -21.
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* we added the square of half the x-coefficient inside parentheses, and its opposite outside parentheses. This makes the expression inside parentheses a perfect square trinomial.