Y=0.09-x^2

Solution for Y=0.09-x^2 equation:

=0.09-Y^2

We move all terms to the left:

-(0.09-Y^2)=0

We get rid of parentheses

Y^2-0.09=0

a = 1; b = 0; c = -0.09;
Δ = b2-4ac
Δ = 02-4·1·(-0.09)
Δ = 0.36
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{0.36}}{2*1}=\frac{0-\sqrt{0.36}}{2}
=-\frac{\sqrt{}}{2}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{0.36}}{2*1}=\frac{0+\sqrt{0.36}}{2}
=\frac{\sqrt{}}{2}
$