Need some help in Algebra 2

Question

znappydooz · Answer

What is the equation of the following graph in vertex form?

znappydooz · Answer

attachment

znappydooz · Answer

A: y = (x − 1)2
B: y = (x − 1)2 + 1
C: y = (x + 1)2 − 1
D: y = (x + 1)2

mathmale · Answer

The equation "in vertex form" is y-k=a(x-h)^2.  Familiar with this?

mathmale · Answer

Please identify the coordinates of the vertex as showin in the illustration.  Also please do the same with the y-intercept.

znappydooz · Answer

I dont get the vertex form @mathmale...
Sorry, i had to do something else

mathmale · Answer

In the vertex form, you see y-k and x-h.  If you're told that the vertex is at the point (-1,0), then h has the value -1 and k has the value 0.  

The letter a represents a constant multiplier which governs whether your parabola opens up widely or narrowly.

(x,y) represents any point which is found on the graph.

mathmale · Answer

You are given the vertex, and also you're given one point that lies on the graph.

Substitute these values into the vertex form I've given you (above).

As before, (h,k) is the vertex; the illustration shows that the vertex is at which point?
There's one other point shown on this graph.  What are its coordinates?  In other words, what are the values of x and y?

If you can answer these questions, you'll have four numbers to substitute into the equation.  The only quantity not given is "a,"  whose value you can find through algebra.

mathmale · Answer

If any of this is unclear to you, just ask questions for clarification.

znappydooz · Answer

(0)-(-1)=a(0-1)^2
Would that be the proper way to rewrite it?

mathmale · Answer

Hey, that looks good!  Does this give you enuf info from which to find the value of 'a?'

znappydooz · Answer

Do I just solve that now?

mathmale · Answer

Yes.  Try it.  We'll need to check the value of 'a' we find to ensure that it's correct.

znappydooz · Answer

I ended up with a = 1

mathmale · Answer

So did I!  Now please write the equation in vertex form.  This time, do not substitute any values for x and y; just write x and y.  (h,k) is (-1,0), as before.

znappydooz · Answer

Do you mean y-(-1)=a(x-1)^2 @mathmale?

mathmale · Answer

Remember that the vertex is at (-1,0).  Therefore, h=-1 and k=0.
So you should have y-0=(x-[-1])^2.  Simplify that.

mathmale · Answer

So did I!  Now please write the equation in vertex form.  This time, do not substitute any values for x and y; just write x and y.  (h,k) is (-1,0), as before.

mathmale · Answer

OpenStudy has been down, so my posts may appear out of order.  Sorry.

Sorry, too, that I need to get off the 'Net now.  Good luck to you!