how to convert a vertex to an equation?

Question

anonymous · Answer

i guess you would use the vertex equation
$$y=a(x-h)^2+k$$

anonymous · Answer

what is H stand for cuz i have it as a coordinate how would i plug the numbers in?

anonymous · Answer

(h,k) is the vertex
h is the x-coordinate and k is the y coordinate

anonymous · Answer

so how would i do this (7.17,-.50)

anonymous · Answer

is that all the information you were given?

anonymous · Answer

no i  have an equation which is y=.23x^2-3.30x+11.34 then i had to find the vertex which i did and got (7.17,-.50) then it says to write it as an equation

anonymous · Answer

ok hold on a minute

anonymous · Answer

$$y=.23(x-7.17)-.50$$

anonymous · Answer

how is that?

anonymous · Answer

the vertex equation is $$y=a(x-h)^2+k$$ to find the vertex (h,k) you can use the formula $$[(-b/2a),(c-b^2/4a)]$$ and when you do that you get the coordinates you got before (7.17,.50)
to find the a of the equation just use the a of the equation given which was .23
so then you just plug it all in and you get $$y=.23(x-7.17)^2-.49$$