Question

In the following, find the value of k for which the given value is a solution of the given equation:

`kx^2 + sqrt2x - 4 = 0, x = sqrt2`

Answer 1

We are given here that,

`kx^2+sqrt2x-4=0`, `x=sqrt2`

Now, as we know that `x=sqrt2` is a solution of the quadratic equation, hence it should satisfy the equation. Therefore substituting `x=sqrt2` in the above equation gives us,

`kx^2+sqrt2x-4=0`

`k(sqrt2)^2+sqrt2(sqrt2)-4=0`

2k + 2 - 4 = 0

2k - 2 = 0

2k = 2

`k=2/2`

k = 1

Hence, the value of k = 1.