Respuesta :
ANSWER
The correct option is D.
EXPLANATION
If the parabola touches but does not cross the x-axis at
[tex]x = - 6[/tex]
Then it means the root
[tex]x = - 6[/tex]
repeats itself 2 times.
In order words the root
[tex]x = - 6[/tex]
has a multiplicity of 2.
We can therefore write the equation
[tex] {(x + 6})^{2} = 0[/tex]
[tex](x + 6)(x + 6) = 0[/tex]
We expand these to obtain
[tex] {x}^{2} + 6x + 6x + 36 = 0[/tex]
This implies that
[tex]{x}^{2} + 12x + 36 = 0 - - - (1)[/tex]
When we multiply through equation one by
[tex] - 1[/tex]
we obtain,
[tex] - {x}^{2} - 12x - 36 - - (2)[/tex]
The functions that corresponds to equation (1) and (2) are:
[tex]f(x) = {x}^{2} + 12x + 36[/tex]
and
[tex]f(x) = - {x}^{2} - 12x - 36[/tex]
respectively.
The above two parabolas have root
[tex]x = - 6[/tex]
that does not cross the x-axis
The correct option is D.
EXPLANATION
If the parabola touches but does not cross the x-axis at
[tex]x = - 6[/tex]
Then it means the root
[tex]x = - 6[/tex]
repeats itself 2 times.
In order words the root
[tex]x = - 6[/tex]
has a multiplicity of 2.
We can therefore write the equation
[tex] {(x + 6})^{2} = 0[/tex]
[tex](x + 6)(x + 6) = 0[/tex]
We expand these to obtain
[tex] {x}^{2} + 6x + 6x + 36 = 0[/tex]
This implies that
[tex]{x}^{2} + 12x + 36 = 0 - - - (1)[/tex]
When we multiply through equation one by
[tex] - 1[/tex]
we obtain,
[tex] - {x}^{2} - 12x - 36 - - (2)[/tex]
The functions that corresponds to equation (1) and (2) are:
[tex]f(x) = {x}^{2} + 12x + 36[/tex]
and
[tex]f(x) = - {x}^{2} - 12x - 36[/tex]
respectively.
The above two parabolas have root
[tex]x = - 6[/tex]
that does not cross the x-axis