Question

If x=-1/2 is a zero of the polynomial p(x)= 2x3+kx2-11x-6, find the value of k

REPLY ASAP!

Answer 1

Answer:

k = - 3

Step-by-step explanation:

In the question

P(x) = 2x^{3}\ -\ kx^{2} \ +\ 3x\ +\ 10P(x)=2x3 − kx2 + 3x + 10

x\ +\ 2 = 0x + 2=0

x = - 2x=−2

According to the question

When we put x = - 2, the P(-2) should be equal to zero.

So,

P(x) = 2x^{3}\ -\ kx^{2} \ +\ 3x\ +\ 10P(x)=2x3 − kx2 + 3x + 10

0 = 2(-2)^{3}\ -\ k(-2)^{2} \ +\ 3(-2)\ +\ 100=2(−2)3 − k(−2)2 + 3(−2) + 10

0 = - 16 - 4k - 6 + 10

0 = - 4k - 12

4k = - 12

k = - 12/4

k = - 3

Hence the value of k = - 3.