Y=-0.07x^2+15

Solution for Y=-0.07x^2+15 equation:

=-0.07Y^2+15

We move all terms to the left:

-(-0.07Y^2+15)=0

We get rid of parentheses

0.07Y^2-15=0

a = 0.07; b = 0; c = -15;
Δ = b2-4ac
Δ = 02-4·0.07·(-15)
Δ = 4.2
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{4.2}}{2*0.07}=\frac{0-\sqrt{4.2}}{0.14}
=-\frac{\sqrt{}}{0.14}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{4.2}}{2*0.07}=\frac{0+\sqrt{4.2}}{0.14}
=\frac{\sqrt{}}{0.14}
$