Question

if -1 is a zero of polynomial 2x^+kx then find the value of k​

Answer 1

If (-1) is the zero of the polynomial

$2 {x}^{2} + kx$

Then required expression would be:

$f( - 1) = 2 {( - 1)}^{2} + k( - 1) = 0 \\ = > 2 + ( - k) = 0 \\ = > - k = - 2 \\ = > k = 2$

HOPE THIS COULD HELP!!

Answer 2

GIVEN:-

$f(x) = {2x}^{2} + kx$

$- 1 \: is \: a \: zero \: of \: f(x)$

TO FIND :- Value of x

SOLUTION :-

When put the value of zero in place of x its value become equals to 0.

If -1 is zero of this polynomial then required expression will be equal to zero.

Therefore, we will form the equation and solve the equation as follows ;

$f( - 1) = 2 { (- 1)}^{2} + - 1k = 0 \\ \\ \\ \implies 2 - k = 0 \\ \\ \\ \implies \boxed{k = 2}$

Therefore, the value of k is 2.