Question

if one root of quadratic equation 2x^2+kx-6=0 is 2 find k also other root.

Answer 1

let another to be p ,
use sum of roots is = -b/a = -k/2 = (p+ 2)
and prod of roots = c/a =6/3 = (p*2)
and solve for k

Answer 2

Since 2 is a root of the given equation
Putting x=2 in the eqn. We get,
2×4+2k-6=0
2k= -2
K = -1
Let alpha and beta be the roots of the eqn.
alpha×beta= c/a
2×beta= -6/2=-3
Beta= -3/2
Therefore the other root is -3/2