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Re: quadratic formula
Posted:
Oct 21, 2012 11:06 AM


Thank you for your explanation, Frederick. You are correct in how I should have interpreted that question in the first place. I reread the question and came to the conclusion that you did. I reviewed the wiki on completing the square and that was the clue to the required solution. Appreciate your time and insight into that problem. Thanks
s
On Thu, 18 Oct 2012 14:13:38 +0100, Frederick Williams <freddywilliams@btinternet.com> wrote:
>stoneboy wrote: >> >> my apologies. I should have used spaces for clarity. add to that I >> made a typo. darn it. sorry to waste your time folks. >> >> if p(x) = ax^2 + bx + c is a second degree polynomial, then >> prove >> >> >> p(x) = a(x+b/2a)^2  ( (b^2  4ac) / 4a ) >> >> funny how they want me to derive the latter from the former. Guess I >> am a little lost. > >It seems to be an odd question. To prove that the second expression for >p(x) is equal to the first, just multiply out the RHS of the second >expression. Far more sensible is to ask: given 'ax^2 + bx + c' how does >one get 'a(x+b/2a)^2  ((b^2  4ac)/(4a))'? The answer to that is 'by >completing the square'. See >http://en.wikipedia.org/wiki/Completing_the_square, for example.



