Question

If alpha and beta are the zeros of the polynomial x2-6x+k find the value of k such that (alpha +beta)2 -2 alpha*beta=40

Answer 1

Answer:

$\alpha + \beta = 6 \\ \alpha \beta = k \\ hence \: \: ( \alpha + \beta )^{2} - 2 \alpha \beta = 40 \\ \\ 36 - 2k = 4 0 \\ k = - 2$