Y3=y2-y1=

Solution for Y3=y2-y1= equation:

3=Y2-Y1=

We move all terms to the left:

3-(Y2-Y1)=0

We add all the numbers together, and all the variables

-(+Y^2-1Y)+3=0

We get rid of parentheses

-Y^2+1Y+3=0

We add all the numbers together, and all the variables

-1Y^2+Y+3=0

a = -1; b = 1; c = +3;
Δ = b2-4ac
Δ = 12-4·(-1)·3
Δ = 13
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{13}}{2*-1}=\frac{-1-\sqrt{13}}{-2}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{13}}{2*-1}=\frac{-1+\sqrt{13}}{-2}
$