Question

plz tell this answer​

Answer 1

1)
Equation = px^2 + qx + r
Let the roots of equation be A and B
Given that, A = 2B

A + B = -q/p = 3B
Or, B = -q/3p. ............... (1)

AB = 2B^2 = r/p
Or, B^2 = r/2p..............(2)

Equating 1 & 2 :-
r/2p = q^2/ 9p^2

Or,
9pr = 2q^2


2)
Given that one zero is negative of the others.
Let the zeros be x and -x.

Sum of zeros = 8k/4 = 2k
( x + (-x)) = 2k

Hence, K = 0