# Unknown Value of "x" in Quadratic Equation x2 - 2x - 1 = 0 2.4142 & -0.4142 are the roots of quadratic equation x2 - 2x - 1 = 0. Users may replace the input values of this equation x2 - 2x - 1 = 0 to verify the similar calculations or generate complete work with steps to find what is the unknown or root value of x.

## Work with Steps for x2 - 2x - 1 = 0

The below work with steps may helpful for grade school students to understand how to find unknown or root values of x for quadratic equation x2 - 2x - 1 = 0 or to solve the worksheet problems. step 1 Address the input parameters and values
Quadratic Equation : x2 - 2x - 1 = 0

step 2 Substitute a , b and c values in below formula

x = - b ± b² - 4ac2a

=-(-2) ± (-22 - 4 (1) (-1))2(1)

=4 - 4 (1)(-1)2

=4 + 42

=82

step 3 Solve the above expression for minus & plus values
x1 = 2 + 82

= 2 + 2.8284/2

x2 = 2 - 82

= 2 - 2.8284/2

step 4 By simplifying the above expressions for x1 & x2
x1 = 4.8284/2
x1 = 2.4142
x2 = -0.8284/2
x2 = -0.4142

x1 = 2.4142 & x2 = -0.4142 are the roots for equation x2 - 2x - 1 = 0 