2x^2+4x-3 in the form of f(x)=a(x-h)^2+k

Question

nowhereman · Answer

Those two forms are equal if the coefficients are the same. So look at $$2x^2 + 4x - 3 = ax^2 - 2ahx-h^2+k$$ identify the coefficients and solve for a, h and k.

radar · Answer

I am treading on dangerous ground here.  When i substitute the coefficients I come up with a=2,  h=1 and k=-3$$f(x)=2(x-1)^{2}-3$$
Not 100% sure about it though.  What have you come up with?

radar · Answer

the k is wrong it has to be -5

radar · Answer

Hopefully nowhereman will bail me out of this quagmire!

nowhereman · Answer

To finish this, you get (sorry should be +a in front of h^2 up there): $$2 = a,\quad 4 = -2ah,\quad -3 = ah^2 + k$$ which lead to $$ a = 2,\quad h = -1,\quad k = -5$$ so that you have $$2x^2 + 4x - 3 = 2(x+1)^2-5$$