Question

If one root of the equation 4x^2-8kx-9=0 is negative of the other, then find the value of k and find the zeros

Answer 1

one root be u other be -u
u+(-u)=-b/a
0=8k/4
so k=0

u×-u=-9/4
-u^2=-9/4
u^2=9/4
u=√9/4
u=3/2

so two zeroes r 3/2 and -3/2

Answer 2

Given; that one root of the equation 4x^2-8kx-9=0 is negative of the other

To Find; the value of k and find the zeros

Solution; It is given one root is negative if the other so let one root as z then the other will be -z

Sum of roots=-b/a

0=8k/4

k=0

Product of roots =c/a

-z^2=-9/4

z=3/2

Hence the roots are 3/2 and -3/2 and the value of k is zero