Given that the equation below has equal roots, find the value of k:

kx² - 4x + k - 3 = 0

I've never seen this before. how would it be done?

Printable View

- Nov 3rd 2008, 10:43 AMdb5vryquadradic equation
Given that the equation below has equal roots, find the value of k:

kx² - 4x + k - 3 = 0

I've never seen this before. how would it be done? - Nov 3rd 2008, 10:46 AMMoo
Hello,

Do you know about the discriminant $\displaystyle \Delta$ ?

If $\displaystyle \Delta>0$, then there are 2 distinct real roots.

If $\displaystyle \color{red} \Delta=0$, then there are 2 equal real roots (and the polynomial is proportional to a perfect square)

If $\displaystyle \Delta <0$, then there is no real root.

In a polynomial ax²+bx+c, the discriminant $\displaystyle \Delta=b^2-4ac$