2.8=y2

Solution for 2.8=y2 equation:

2.8=y2

We move all terms to the left:

2.8-(y2)=0

We add all the numbers together, and all the variables

-1y^2+2.8=0

a = -1; b = 0; c = +2.8;
Δ = b2-4ac
Δ = 02-4·(-1)·2.8
Δ = 11.2
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{-(0)-\sqrt{11.2}}{2*-1}=\frac{0-\sqrt{11.2}}{-2}
=-\frac{\sqrt{}}{-2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{11.2}}{2*-1}=\frac{0+\sqrt{11.2}}{-2}
=\frac{\sqrt{}}{-2}
$