Question

is one root of the quadratic equation 2 X square + 2 X + K is equal to zero is minus 1 upon 3 then find the value of k​

Answer 1

Step-by-step explanation:

p(x) =2x^2 + 2x +k =0

p(-1/3) = 2*(-1/3)^2 + 2*-1/3 +k=0

=2 *1/9 +-2/3 +k=0

2/9 +-2/3 +k=0

2/9 +k = 3/2

k =3/2 - 9/2

k= -6/2

k =-3

Answer 2

The value of $k=\dfrac{4}{9}$

Explanation:

The given quadratic equation : $2 x^2+ 2x + k=0$

The root of the quadratic equation : $x=\dfrac{-1}{3}$

We know that if a is the root of f(x) , then  f(a)=0.

Thus ,

$2 (\dfrac{-1}{3})^2+ 2(\dfrac{-1}{3}) + k=0\\\\\Rightarrow\ 2\times(\dfrac{1}{9})-\dfrac{2}{3}+k=0\\\\\Rightarrow\ \dfrac{2}{9}-\dfrac{2}{3}+k=0\\\\\Rightarrow\ \dfrac{2-3(2)}{9}+k=0\\\\\Rightarrow\ \dfrac{-4}{9}+k=0\\\\\Rightarrow\ k=\dfrac{4}{9}$

Hence, the value of $k=\dfrac{4}{9}$

# Learn more :

If x is equal to 3 is 1 root of the quadratic equation X square minus 2 k x minus 6 is equal to zero then find the value of k

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