Question

x^2-2x-4=0 use formula and find value

Answer 1

using determinant method
D=b^2-4ac
=4-4(1)(-4)
=20

now thw value of x
x=-b+-underoot_D/2a
=2+- 2underoot5/2
=2(1+underoot 5)/2
===answer= 1+underoot 5