Unknown Value of "x" in Quadratic Equation x2 - x - 1 = 0
1.618 & -0.618 are the roots of quadratic equation x2 - x - 1 = 0. Users may replace the input values of this equation x2 - x - 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 - x - 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 - x - 1 = 0 or to solve the worksheet problems.
step 1 Address the input parameters and values
Quadratic Equation : x2 - x - 1 = 0
step 2 Substitute a , b and c values in below formula
x = - b ± √b² - 4ac2a
=-(-1) ± √(-12 - 4 (1) (-1))2(1)
=1± √1 - 4 (1)(-1)2
=1± √1 + 42
=1± √52
step 3 Solve the above expression for minus & plus values
x1 = 1 + √52
= 1 + 2.2361/2
x2 = 1 - √52
= 1 - 2.2361/2
step 4 By simplifying the above expressions for x1 & x2
x1 = 3.2361/2
x1 = 1.618
x2 = -1.2361/2
x2 = -0.618
x1 = 1.618 & x2 = -0.618 are the roots for equation x2 - x - 1 = 0
