Teg21
contestada

What is the line of symmetry for the graph of y = -3x2 + 12x - 11?

x = -4
x = -2
x = 2

Respuesta :

it would be the last one, x=2

Answer:  The correct option is (C) x = 2.

Step-by-step explanation:  We are given to select the correct option that gives the line of symmetry for the graph of the following equation:

[tex]y=-3x^2+12x-11~~~~~~~~~~~~~~~~~~~~~~~~~~(i)[/tex]

We know that the graph of a quadratic equation in the form

[tex]y=ax^2+bx+c[/tex] has as its line of symmetry given by:

[tex]x=-\dfrac{b}{2a}.[/tex]

From equation (i), we have

a = - 3,  b = 12  and  c = -11.

Therefore, the line of symmetry for the given equation is

[tex]x=-\dfrac{b}{2a}\\\\\\\Rightarrow x=-\dfrac{12}{2\times (-3)}\\\\\\\Rightarrow x=\dfrac{12}{6}\\\\\\\Rightarrow x=2.[/tex]

Thus, the required line of symmetry is  x = 2.

Option (C) is correct.