I need help on this question and quick >< Find the value of k for which 5 + 4x - x^2 = k, has equal roots. To just lets you's know, k=9.
Follow Math Help Forum on Facebook and Google+
Originally Posted by xornr89 I need help on this question and quick >< Find the value of k for which 5 + 4x - x^2 = k, has equal roots. To just lets you's know, k=9. By completing the square you know you want which returns so substituting this in you get so x-2=0 and -(x-2)=0 Both of these values return x=2, thus they are the same.
Alternately we could do this with the discriminant formula.. For equal roots, D = 0. So x = 2. Substituting.. k = 9.
View Tag Cloud