c2=2.1

Solution for c2=2.1 equation:

c2=2.1

We move all terms to the left:

c2-(2.1)=0

We add all the numbers together, and all the variables

c^2-2.1=0

a = 1; b = 0; c = -2.1;
Δ = b2-4ac
Δ = 02-4·1·(-2.1)
Δ = 8.4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{8.4}}{2*1}=\frac{0-\sqrt{8.4}}{2}
=-\frac{\sqrt{}}{2}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{8.4}}{2*1}=\frac{0+\sqrt{8.4}}{2}
=\frac{\sqrt{}}{2}
$