a) Find the values of k and c in the equation y=c+kx-x^2
b) Find the co-ordinates of the highest point of the graph.

 rpray2007 Posts: 320, Reputation: 110 Full Member #2 Apr 10, 2012, 04:59 PM
Would be glad to help and if you tell us where you are stuck, we're more than happy to help.

$x{\small_1}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

In your case, $k$ is the same as $b$ and $a$ is $-1$

Good luck.
 catfish- Posts: 3, Reputation: 1 New Member #3 Apr 10, 2012, 05:23 PM
Thank you for your help, I don't know how to use the quadratic formula to solve this. Will the answer be numbers or an expression?
 rpray2007 Posts: 320, Reputation: 110 Full Member #4 Apr 11, 2012, 10:27 PM
It will be an expression as you do not have any number for $c, k$ and $b$.

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