How do you solve using the quadratic formula x^2-x= -1?

1 Answer
May 15, 2015

Write your equation as:
x^2-x+1=0 (taking -1 to the right and changing sign)
now your equation is in the form: ax^2+bx+c=0 where the numerical coefficients are:
a=1
b=-1
c=1
You can use them into the Quadratic Formula given as:
x_(1,2)=(-b+-sqrt(b^2-4ac))/(2a)
So:
x_(1,2)=(1+-sqrt(1-4(1*1)))/(2)
x_(1,2)=(1+-sqrt(-3))/(2)
The negative argument of your square root cannot give you a real number.
The solutions of your equation will be two Complex Numbers .
You can write:
x_(1,2)=(1+-sqrt(-1*3))/(2)
x_(1,2)=(1+-isqrt(3))/(2) where i=sqrt(-1)