SOLUTION: I can't seem to get this no matter how hard I try, think you can show me what I am doing wrong? I thank you in advance for using your own personal time to help an idiot like me. F

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Question 24421: I can't seem to get this no matter how hard I try, think you can show me what I am doing wrong? I thank you in advance for using your own personal time to help an idiot like me.
For the function y=x squared -4x-5, perform the following tasks:
a) Put the function in the form y=a(x-h)squared+k.
b) What is the line of symmetry?
c)Graph the function using the equation in part a. Explain why it is not necessary to plot points to graph when using y=a(x-h)squared+k.
d) How does this graph compare to the graph of y=x squared?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) y+=+x%5E2+-4x+-5
convert to the form
(2) y+=+a%28x+-+h%29%5E2+%2B+k
I can factor the equation , but that doesn't help me. It factors to:
%28x+-+5%29%28x+%2B+1%29
I'll expand the form I'm trying to get it into
(3) y+=+a%28x%5E2+-+2+%2A+h+%2A+x+%2B+h%5E2%29+%2B+k
Now I've got to make it fit equation (1)
(4) y+=+a%28x%5E2+-2%2A%282%29%2Ax+%2B+%282%29%5E2%29+-+9
That will make this form equal equation (1), but I have to make a = 1
equation (4) reduces to:
(5) y+=+%28x+-+2%29%5E2++-+9
h = 2
k = -9
a = 1
what is the line of symmetry?
On the line of symmetry, +x gives me the same y as -x.
suppose the line of symmetry is x = 2, making y = -9
Now lets make x = (2 + j) or x = (2 - j)
(5) ends up looking like:
y+=+%28%2Bj%29%5E2+-+9
or
y+=+%28-j%29%5E2+-+9
clearly the sign of j doesn't make a difference, so being on either side of
x = 2 gives the same y.
x = 2 is the axis of symmetry
I guess the answer to (c) is that you can look at the equation and tell what
the important features are.
as for (d), put y = x into form (2), then
h = 0
k = 0
a = 1
The axis of symmetry is x = 0