Question

if 1/3 is root of x2+kx-1=0 then value of k is​

Answer 1

Answer:

(1/3)² +k/3-1=0

1/9+k/3-1=0

1+3k-9/9=3k-8/9=0

3k-9=0

3k=9

k=3

Answer 2

Answer:

The value of k according to the quadratic equation is k=$\frac{8}{3}$

Step-by-step explanation:

We know that,

⇒ Root of an equation is the value of the variable that satisfies the quadratic equation.

According to the question,

$\frac{1}{3}$ is the root of the equation $x^{2} +kx-1=0$

Substituting x= $\frac{1}{3}$  in the quadratic equation,

$\frac{1}{3} ^{2}+k \times\frac{1}{3} -1=0$

$\frac{1}{9} +\frac{k}{3} -1=0$

$\frac{k}{3} = \frac{8}{9}$

k=$\frac{8}{3}$

∴

The value of k=$\frac{8}{3}$

The correct answer is k=$\frac{8}{3}$