Answer:
A. x-intercepts: (4,0),(-2,0)
C. Vertex: (1,-9)
Step-by-step explanation:
We have been given factored form of a quadratic equation [tex]y=(x-4)(x+2)[/tex]. We are asked to find vertex and x-intercepts of our given equation.
We know that x-intercepts of a graph are those points at which graph touches or crosses x-axis and y-coordinates of x-intercepts are always zero.
So we will substitute [tex]y=0[/tex] in our given equation to find the x-intercepts.
[tex]0=(x-4)(x+2)[/tex]
[tex](x-4)=0\text{ or }(x+2)=0[/tex]
[tex]x-4+4=0+4\text{ or }x+2-2=0-2[/tex]
[tex]x=4\text{ or }x=-2[/tex]
Since y-coordinates of x-intercepts will be 0, therefore, x-intercepts of the graph will be (4,0), (-2,0) and option A is the correct choice.
To find the vertex of the parabola, we will expand our given expression using FOIL.
[tex](x-4)(x+2)[/tex]
[tex]x*x+x*2-4*x-4*2[/tex]
[tex]x^2+2x-4x-8[/tex]
[tex]x^2-2x-8[/tex]
We will use formula [tex]\frac{-b}{2a}[/tex] to find the x-coordinate of vertex of parabola, where, a and b represents the coefficient of [tex]x^2\text{ and }x[/tex] respectively.
[tex]\text{x-coordinate of vertex}=\frac{-(-2)}{2*1}[/tex]
[tex]\text{x-coordinate of vertex}=\frac{2}{2}=1[/tex]
Now we will substitute [tex]x=1[/tex] in the expression to find the y-coordinate of parabola.
[tex]\text{y-coordinate of vertex}=1^2-2*1-8[/tex]
[tex]\text{y-coordinate of vertex}=1-2-8[/tex]
[tex]\text{y-coordinate of vertex}=-9[/tex]
Therefore, the vertex of parabola will be at point (1,-9) and option C is the correct choice.
Answer:
A and C is correct people
Step-by-step explanation:
A p e x approved
