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1 vote
April rewrote a quadratic function in vertex form.

h(x) = 5x2 – 30x + 30
Step 1: h(x) = 5(x2 - 6x+ + 30
Step 2: h(x) = 5(x2 - 6x + 9) + 30 – 45
Step 3: h(x) = 5(x - 3)2 + 15.
April said that the vertex is (3, 15). Is April correct?

1 Answer

3 votes

Final answer:

April correctly transformed the quadratic function into vertex form, and the resulting vertex is (3, 15), as determined by the completion of the square method.

Step-by-step explanation:

April is indeed correct about the vertex of the function h(x). The vertex form of a quadratic function is h(x) = a(x - h)^2 + k, where the point (h, k) is the vertex of the parabola. April has rewritten the quadratic function h(x) = 5x^2 - 30x + 30 into vertex form as h(x) = 5(x - 3)^2 + 15, indicating that the vertex is at (3, 15). This can be verified through the completion of the square method, where a perfect square trinomial is created by adding and subtracting the appropriate constant term. April added and subtracted 9 inside the parentheses, which is (6/2)^2, to keep the equation equivalent. Finally, she factored out the coefficient of the quadratic term (5) before completing the square, which is correct.

User Josef Borkovec
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