The x intercepts are determide when you calculated the equation when y=0
To find the x-coordinate of the vertex you have to apply the next formula:
Where you follow the form of the equation:
X-intercep:
1. In this case if we have the equation in the form: x( x - 2) we can know that y=0 when one of the terms is 0:
y=0 when:
x=0 x-2=0
x= - 22. y=0 when:
x-4=0
x=4 x+5=0
x=-5
3. y=0 when:
x-1=0
x=1 x-5=0
x=5x-coordinate of the vertex:
To identify the coeficeints a and b we express the equation in a different form, we have to multiply. Then we can apply the formula to find the x coordinate of the vertex, as follow:
1.
2.
3.