Question

If one of zero of the polynomial 2x2-5x-(2k+1)= is twice the other find value of k also find the zeores

Answer 1

Answer

Let first zeros be r then second will be 2r

from the equation, a=2, b=-5, and c=2k+1

Sum of zeros, r+2r = (-b/a)= -(-5/2)

3r =5/2

r=5/6

product of zeros, r*2r =(c/a)=(2k+1)/2

2r^2 =(2k+1)/2

2*(5/6)^2 =(2k+1)/2

2k+1 =(2*25*2)/36=25/9

2k=(25-9)/9=16/9

k=8/9