4-4r^2=2r^2-2

Solution for 4-4r^2=2r^2-2 equation:

4-4r^2=2r^2-2

We move all terms to the left:

4-4r^2-(2r^2-2)=0

We get rid of parentheses

-4r^2-2r^2+2+4=0

We add all the numbers together, and all the variables

-6r^2+6=0

a = -6; b = 0; c = +6;
Δ = b2-4ac
Δ = 02-4·(-6)·6
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12}{2*-6}=\frac{-12}{-12}
=1
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12}{2*-6}=\frac{12}{-12}
=-1
$