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

2 Answers
Apr 29, 2018

x_1=(1+sqrt(3))/2 or x_2=(1-sqrt(3))/2

Explanation:

2x^2-2x=1|-1
2x^2-2x-1=0|:2
x^2-x-1/2=0
x_(1,2)=-(p/2)+-sqrt((p/2)^2-q)
x_(1,2)=-(-1/2)+-sqrt((-1/2)^2-(-1/2))
x_(1,2)=1/2+-sqrt(1/4+1/2)=1/2+-sqrt(3)/2

Apr 29, 2018

x=(1pmsqrt3)/2

Explanation:

Minus 1:

2x^2-2x-1=0

Use the formula:

rArr x=-bpm(sqrt(b^2-4ac))/(2a)

Use the quadratic to find the values:

2x^2-2x-1

a=2

b=-2

c=-1

therefore rArr x=-(-2)pm(sqrt((-2)^2-4(2)(-1)))/(2(2))

rArr x=(1pmsqrt(3))/(2)

rArr (1+sqrt3)/2, and (1-sqrt3)/2

You could change these to decimals or leave it in surd form, however, I will leave in surd form.