SOLUTION: Consider the parabola: y=x^2-6x+5. (i) Complete the square. (ii) Give the Vertex. (iii) Give the x- and y-intercepts. (iv) Graph the parabola. I have been working on t

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Consider the parabola: y=x^2-6x+5. (i) Complete the square. (ii) Give the Vertex. (iii) Give the x- and y-intercepts. (iv) Graph the parabola. I have been working on t      Log On


   



Question 34600: Consider the parabola: y=x^2-6x+5.
(i) Complete the square.
(ii) Give the Vertex.
(iii) Give the x- and y-intercepts.
(iv) Graph the parabola.
I have been working on this one but cannot get it right. Please help.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
x^2-6x+5=y
(x^2-6x =y-5
Complete the square on the left side and maintain the equal sign, as follows;
x^2-6x+3^2 = y-5+3^2
Factor the left side and simplify the right side to get:
(x-3)^2 = y+4
a) The vertex is (3,-4)
b) To get the x-intercept, let y=0. Then
x^2-6x+5=0
(x-5)(x-1)=0
x=5 or x=1 (these are the x-intercepts
c) To get the y-intercept, let x=0
0^2-6(0)+5=y
y=5 This is the y intercept.
d) Graph as follows:
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-6x%2B5+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-6%29%5E2-4%2A1%2A5=16.

Discriminant d=16 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--6%2B-sqrt%28+16+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-6%29%2Bsqrt%28+16+%29%29%2F2%5C1+=+5
x%5B2%5D+=+%28-%28-6%29-sqrt%28+16+%29%29%2F2%5C1+=+1

Quadratic expression 1x%5E2%2B-6x%2B5 can be factored:
1x%5E2%2B-6x%2B5+=+1%28x-5%29%2A%28x-1%29
Again, the answer is: 5, 1. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-6%2Ax%2B5+%29