How do you solve # -x^2 +2x +1 = 0# using the quadratic formula?

1 Answer
May 24, 2016

Answer:

#x={-sqrt2+1,sqrt2 +1}#

Explanation:

#-x^2+2x+1=0#

#ax^2+bx+c=0#

#Delta=sqrt(b^2-4*a*c)#

#x=(-b±Delta)/(2a)#

#a=-1#
#b=2#
#c=1#

#Delta=sqrt(2^2+4*1*1)#

#Delta=sqrt(4+4)#

#Delta=sqrt 8#

#Delta=2sqrt2#

#x_1=(-2-2sqrt2)/(2*(-1)#

#x_1=-2((1+sqrt2))/(-2)#

#x_1=1+sqrt2#

#x_2=(-2+2sqrt2)/(-2)#

#x_2=(-2(1-sqrt2))/(-2)#

#x_2=1-sqrt2#