Question

one zero of the polynomial 4x² – (2k + 1)x – 9 = 0 is the additive inverse of the other, then value of k is​

Answer 1

The question says one root is negative of others.

So, the sum of the roots must be zero.

For any quadratic equation

Like : ax2+bx+c=0

The sum of roots is given by a−b

So, in this equation : 4x2−8ka−9

b=−8k & a=4

So, 0=a−b

4−(−8k)=0

2k=0⇒k=0