If one zero of the quadratic polynomial f(x) = 4x^{2} - 8kx - 9 is negative of the other, find the value of k.

^{2}- 8kx - 9 with ax

^{2}+bx+c we get

a=4; b=-8k and c=-9.

Since one root is the negative of the other, let us assume that the roots are p an -p.

Sum of the roots, a+(-a)=-b/a=-(-8k)/4

0=2k

k=0

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