Question

If zero of the polynomial x square-2kx-8 is 2 then value of k

Answer 1

p(x) = x² - 2kx - 8

if 2 is the zero of p(x), then

p(2) = 0

So,

=> (2)² - 2(2)k - 8 = 0

=> 4 - 4k - 8 = 0

=> -4 - 4k = 0

=> 4k = -4

=> k = -4/4

=> k = -1

Hence, Value of k is -1

Answer 2

Step-by-step explanation:

${x}^{2} - 2kx - 8 = 0 \\ = > {2}^{2} - 2 \times k \times 2 - 8 = 0 \\ = > 4 - 4k - 8 = 0 \\ = > - 4k - 4 = 0 \\ = > - 4k = 4 \\ = > k = - 1 \: ans$