as it has real roots this means that you should be using the quadratic formula, the discriminant, which its b^2-4ac. and then make it =0 and then solve it as in finding K... you'll get a fraction as an answer, or you could just put it in decimals, whichever way you like.
Just in case you havent done in quadratic equation... in the example you gave a=K b=8 c=5. soo there you.
for the discriminant (b^2-4ac) i gt 64 - 20k ----->> iz dat ryt????
what do i do next?!?!?!?!?!?!?!?!?! (BTW i aint allowed to use a calc)
Answered Tue 2nd October, 2012 @ 17:25 by Akeel 786
8^2 + 4xkx5 > 0 as has real roots not one root i thought? As one real root is = 0 isnt it?
64 + 20k > 0
20k > -64
K > -64/20
K > -16/5
Thats what i got? Hope it helps even if its wrong you might be able to see where to go next?