Write Standard Quadratic Form: Write the equation in standard quadratic form.To find the roots of the equation, we need to write it in the form ax2+bx+c=0. Subtract 2x and 1 from both sides to get the equation in standard form.x2−2x−1=0
Identify Coefficients: Identify the coefficients a, b, and c. In the equation x2−2x−1=0, the coefficients are: a=1, b=−2, c=−1
Use Quadratic Formula: Use the quadratic formula to find the roots.The quadratic formula is given by 2a−b±b2−4ac. Substitute the values of a, b, and c into the formula.2⋅1−(−2)±(−2)2−4⋅1⋅(−1)
Simplify Square Root: Simplify the expression under the square root. Calculate the discriminant b2−4ac. (−2)2−4⋅1⋅(−1)=4+4=8
Substitute Discriminant: Substitute the discriminant back into the quadratic formula. 22±8
Divide by 2: Simplify the square root of 8. 8 can be written as 4×2, which simplifies to 2×2. (2±2×2)/2
Write Roots in Simplest Form: Simplify the expression by dividing by 2.Divide both terms in the numerator by 2.1±2
Write Roots in Simplest Form: Simplify the expression by dividing by 2.Divide both terms in the numerator by 2.1±2Write the roots in simplest form.The roots of the equation are:x=1+2 and x=1−2
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