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)#