**Q.)One root of X ^{2}+kX-8=0 is square of the other. Then, the value of k is:**

1)2

2)8

3)-8

4)-2

Solution: let the root be a and a

^{2}.

Hence , Sum of the roots = -b/a = -k and Product of the roots = c/a = -8

a + a^{2} = -k

and a * a^{2} = -8 => a^{3} = -8

=> a= -2

Hence , a + a^{2} = -2+(-2)^{2} = -2 + 4 =2 = -k

=> k =-2 Option(4) Ans.