Which statements about the graph of the function f(x) = –x2 – 4x + 2 are true? Check all that apply.
-The domain is {x|x ≤ –2}.
-The range is {y|y ≤ 6}.
-The function is increasing over the interval (–∞ , –2).
-The function is decreasing over the interval (−4, ∞).
-The function has a positive y-intercept.

Respuesta :

statements 2, 3, and 5 are true based on the graph of this function.
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Remark
There is nothing like a graph to settle arguments about which property is to be checked. 

Property One
The graph's domain is (-∞<x<∞) there are no restrictions. So property 1 is false.

Property two
The graph says that property two is true. You could complete the square to confirm it. When you do you get
y = -(x^2 + 4x) + 2
y = -(x^2 + 4x + 4) + 2 + 4
y = -(x + 2)^2 + 6  So the y value must be less that 6 ( or equal to 6)

Property Three
Property 3 is true if you are referring to the domain and neither -2 nor - infinity are included.

Property Four
Property Four is not true, It begins to decrease when x>-2 to + infinity

Property Five
It is positive (2).
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