SOLUTION: I am submitting this problem again because from the last help I got my teacher said that it was wrong. Please help me! Complete the square Give the Vertex Give the Axis Giv

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: I am submitting this problem again because from the last help I got my teacher said that it was wrong. Please help me! Complete the square Give the Vertex Give the Axis Giv      Log On


   

Question 31499: I am submitting this problem again because from the last help I got my teacher said that it was wrong. Please help me!
Complete the square
Give the Vertex
Give the Axis
Give the x-intercepts
Give the y-intercept
Give a point symmetric to the y-intercept.
You must draw the graph using a graphing utility and attach it in your response.
y = x2 -2x-3
He keeps telling me that I need to factor it correctly. I have tried from the example that was given that was kind of like my problem but he told me it was wrong. Could someone please help me with this problem? Thank you so very much.
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
Factorise it: (x-3)(x+1) so the x-intercepts are at x=-1 and x=3

Complete the square: +x%5E2-2x-3+
2a=2
a=1
--> a%5E2+=+1

--> +x%5E2-2x%28%2B1-1%29-3+
--> +%28x%5E2-2x%2B1%29-1-3+
--> +%28x-1%29%5E2-4+

So, the vertex is at (1,-4) meaning that the line of symmetry in the function is at x=1.

Y-intercept is when x=0, so from +y+=+x%5E2-2x-3+, we get
+y+=+%280%29%5E2-2%280%29-3+
--> y= -3.

A point symmetric to the y-intercept (0,-3) is (2,-3) since both points are equi-distant from the line x=1.

All seen on +graph%28300%2C300%2C-6%2C6%2C-10%2C10%2Cx%5E2-2x-3%29+

As for "give the axis"... what axis?

jon.