
Parviz F. answered 03/05/14
Tutor
4.8
(4)
Mathematics professor at Community Colleges
X^2 - X +1 = 0 there is no 2 rational numbers such that X1 + X2= -1 X1 . X2 = 1
To solve use factoring by perfect square:
X^2 - 2 X/ 2 + 1/4 - 1/4 +1 =0
( X + 1/2 ) ^2 = -3/4
X + 1/2 = ±i√3/2
X = 1/2 ± i√3/2
Can use Quadratic formula as well, that is driven from factoring by perfect square method of
aX^2 + bX +c X = -b/2 ±√(b^2 - 4(a)(c))
X = 1/ 2 ±√([ 1^2 - 4(1)(1)] / 2 = 1/2 ±√(3 )/2