Solve x^2 - 8x - 1

Evaluate

x^{2} - 8 x - 1

To find the roots of the expression,set the expression equal to 0

x^{2} - 8 x - 1 = 0

Substitute a= 1,b= - 8 and c= - 1 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{8 \pm ( - 8 ) ^{2} - 4 ( - 1 )}{2}

Simplify the expression

More Steps

x = \frac{8 \pm 68}{2}

Simplify the radical expression

More Steps

x = \frac{8 \pm 2 17}{2}

Separate the equation into 2 possible cases

x = \frac{8 + 2 17}{2} x = \frac{8 - 2 17}{2}

Simplify the expression

More Steps

x = 4 + 17 x = \frac{8 - 2 17}{2}

Simplify the expression

More Steps

x = 4 + 17 x = 4 - 17

Solution

x_{1} = 4 - 17, x_{2} = 4 + 17

Alternative Form

x_{1} \approx - 0.123106, x_{2} \approx 8.123106

Find the roots