Find the least integral value of k for which the quadratic polynomial
(k - 2)x^2 + 8x + k+4 > 0 where x is real.
i am trying to solve the discriminant by equating it to>0
D>0
but i don't think it is correct.
Please provide hints for this solutions.
no it is not ...(k+1)
it is ...(k+4)
i think that i have to first find the zeros of the following
(k-4)(k+6)<0
that is k=-6 and k=4
then try putting any value less than -6 then value between -6 and 4
and at last value greater than 4
thus we will get the solution as -6<k<4 ???
the smallest value of the function:
here
is
to get this value positive D should be negative-------------(I)
and solving according this we get
64-4(k-2)(k+4) < 0
as this may result in correct answer
but as x is real .'. D should be positive or zero--------------(II)
I am confused with (I) (II)
????