Question

What is the first step in writing f(x) = 3x2 + 6x – 8 in vertex form?

Answer 1

Answer:

D. Factor out 3 from the first two terms.

Step-by-step explanation:

According to the Vertex Formula [y = A(X - H)² + K], -H gives you the OPPOSITE terms of what they really are, but in this case, this would not qualify, since the question is asking something totally unique. So, since 3 is your "A", you factor that out, and since 6 is a multiple of 3, it is easy to work with. Anyway, you get this:

y = 3(x + 1)² - 11

I hope this helps you out alot, and as always, I am joyous to assist anyone at any time.

Answer 2

Answer:

  D. Factor out 3 from the first two terms.

Step-by-step explanation:

Vertex form is ...

  y = a(x -h)² +k

where (h, k) is the vertex and "a" is the vertical scale factor.

This equation expands to give ...

  y = ax² -2ahx + ah² +k

Factoring "a" from the terms involving x makes it easy to identify h and so finish putting the equation into vertex form. In this equation, that means the most appropriate first step is ...

  factor out 3 from the first two terms