6.35=r2

Solution for 6.35=r2 equation:

6.35=r2

We move all terms to the left:

6.35-(r2)=0

We add all the numbers together, and all the variables

-1r^2+6.35=0

a = -1; b = 0; c = +6.35;
Δ = b2-4ac
Δ = 02-4·(-1)·6.35
Δ = 25.4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{25.4}}{2*-1}=\frac{0-\sqrt{25.4}}{-2}
=-\frac{\sqrt{}}{-2}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{25.4}}{2*-1}=\frac{0+\sqrt{25.4}}{-2}
=\frac{\sqrt{}}{-2}
$