Question

The a value of a function in the form f(x) = ax2 + bx + c is negative. Which statement must be true?
The vertex is a maximum.
The y-intercept is negative.
The x-intercepts are negative.
The axis of symmetry is to the left of zero.

Answer 1

The correct answer for the question that is being presented above is this one: "The axis of symmetry is to the left of zero." The a value of a function in the form f(x) = ax2 + bx + c is negative. The statement must be true is this The axis of symmetry is to the left of zero.

Answer 2

For this case we have a standard quadratic equation of the form:
 $f (x) = ax ^ 2 + bx + c$
 As the function is negative then the following is true:
 $a \ \textless \ 1$
 Therefore, when the leading coefficient is less than one then:
 1) The parable opens down.
 2) The cutting points with the x axis can be positive or negative
 3) The cutoff point with the y axis can be positive or negative
 4) The axis of symmetry can be to the right or to the left of zero.
 5) The vertex of the parabola is a maximum and this is because the second derivative is negative.

 Answer:
 The vertex is a maximum.