Question

What values of x make the equation x2−2x−1=0 true?

Answer 1

The values of x are 2.41 and -0.41

Explanation:

The given quadratic equation is
`x^2-2x-1=0`

It is required to find the value of x form which the above equation is true. It means we need to solve the above equation for x. The solution of a quadratic equation
`ax^2+bx+c=0` are :

`x=(-b\pm √(b^2-4ac) )/(2a)`

We have, a = 1, b = -2 and c = 1

Thus, plugging all values in formula, we get :

`x=(-b+ √(b^2-4ac) )/(2a),(-b- √(b^2-4ac) )/(2a)\\\\x=(-(-2)+ √((-2)^2-4(1)(-1)) )/(2(1)),(-(-2)- √((-2)^2-4(1)(-1)) )/(2(1))\\\\x=2.41, -0.41`

The values of x are 2.41 and -0.41