Question

What will be the value of k in the polynomial x²+8x+k, If -1 is a zero of the polynomial?​

Answer 1

Hi there !

If -1 is a zero of the polynomial,

Then, 1 is a zero of the polynomial and put 1 to find the value of k.

And it should be zero as it a zero of that polynomial.

=>x²+8x+k

=>(1)²+8(1)+k =0

=>1+8+k=0

=>9+k=0

=>k= -9

Hence, the value of k is -9

You can check by putting this answer in that polynomial.

Thankyou :)

Answer 2

since -1 is the factor of the above polynomial then:-

$p( - 1) = ( - 1)^{2} + 8( - 1) + k = 0$

$1 - 8 + k = 0$

$- 7 + k = 0$

$k = 0 + 7$

$\therefore$$k = 7$

____________________________________

Hope this helps u

pls give it a thanks :)