Question

Solve quadratic equation x²-8x-1=0 by formula method​

Answer 1

x²-8x-1=0

comparing above equation with ax²+bx+c=0

a=1

b=-8

c=-1

x=

`x = \frac{ - b + - \sqrt{ {b}^(2) - 4ac } }{2a}`

=(--8+-√(64-4×1×-1)/2×1

=8+-√(64+4)/2

taking positive

x=(8+√68)/2=2(4+√17)/2=4+√17

taking negative

x=(8-√68)/2=2(4-√17)/2=4-√17