Question

one of roots of quadratic equations is 2xsquare +kx-2=0 is -2,find k​

Answer 1

Answer:

$we \: have \: x \: is \: 2 \\ p(x) = 2x ^{2} + kx - 2 = 0 \\ p(2) = 2 ^{2} + k(2) - 2 = 0 \\ p(2) = 4 + 2k - 2 = 0 \\ \: \: \: \: \: \: = 2 + 2k = 0 \\ \: \: \: \: \: \: \: = 2k = - 2 \\ \: \: \: \: \: \: \: \: = k = - 1$

Answer 2

Answer:

k=3

Step-by-step explanation:

if -2 is one of the root than f(-2)=0

now put x=-2 in equation

and get the value of k