Hi,

Please help me understand an exam question I had last semester. I know how to find the solution if I could use $\displaystyle b^2 = 4ac$ but I wasn't allowed to use that method and with completing the square, I would normally put the equation in unity, but it already is so I can miss that step, then take half the coefficients of the b term, move the constant to the other side of the equation, take half the coefficient of b and put it in a bracket, expand the bracket out to see what I need to add or subtract from the equation and bob should be my uncle, but I cant find the solution!

Right the questions was:

(i) By completing the square, find in terms of k the roots of the equation $\displaystyle x^2 + 2kx -7 = 0 $

Any help would be greatly appreciated!

Thanks,

Kris