d^2=3520

Solution for d^2=3520 equation:

d^2=3520

We move all terms to the left:

d^2-(3520)=0

a = 1; b = 0; c = -3520;
Δ = b2-4ac
Δ = 02-4·1·(-3520)
Δ = 14080
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{14080}=\sqrt{256*55}=\sqrt{256}*\sqrt{55}=16\sqrt{55}$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-16\sqrt{55}}{2*1}=\frac{0-16\sqrt{55}}{2}
=-\frac{16\sqrt{55}}{2}
=-8\sqrt{55}
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+16\sqrt{55}}{2*1}=\frac{0+16\sqrt{55}}{2}
=\frac{16\sqrt{55}}{2}
=8\sqrt{55}
$