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Which statements are true about the graph of the function f(x) = x2 – 8x + 5? Check all that apply.

The function in vertex form is f(x) = (x – 4)2 – 11.
The vertex of the function is (–8, 5).
The axis of symmetry is x = 5.
The y-intercept of the function is (0, 5).
The function crosses the x-axis twice.

Respuesta :

altavistard

Answer:

Step-by-step explanation:

Using "completing the square," write f(x) = x^2 – 8x + 5 in vertex form.  Note:  Use " ^ " to denote exponentiation.

f(x) = x^2 – 8x + 5 = x^2 - 8x + 16 - 16 + 5, or

1)  f(x) =                        (x -4)^2 - 11  This is the function in vertex form.  (TRUE)

2)  The axis of symmetry is x = 4, not x = 5.  (FALSE)

3) The y-intercept of this function is (0, 5) (TRUE)

4)  The function crosses the x-axis twice.

     From the vertex form, (x -4)^2 - 11 , we see that the vertex is at (4, - 11), which is below the x-axis.  Since the parabolic graph opens up, the graph does cross the x-axis twice.  (TRUE)

Answer:

A, D, and E

Step-by-step explanation:

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