hi all, the question is: obtain an inequality satisified by k if the equation below has two distinct real roots

$\displaystyle x^2 - 2x - k = 0$

so i made that into $\displaystyle 4 - 4k > 0$ then

$\displaystyle -4k > -4$ then i would presume the final answer is

$\displaystyle k > 1$

but the books answer is k > -1

why is this? thanks

Mark