4r^2-3.14^2=80

Solution for 4r^2-3.14^2=80 equation:

4r^2-3.14^2=80

We move all terms to the left:

4r^2-3.14^2-(80)=0

determiningTheFunctionDomain
4r^2-80-3.14^2=0

We add all the numbers together, and all the variables

4r^2-89.8596=0

a = 4; b = 0; c = -89.8596;
Δ = b2-4ac
Δ = 02-4·4·(-89.8596)
Δ = 1437.7536
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{1437.7536}}{2*4}=\frac{0-\sqrt{1437.7536}}{8}
=-\frac{\sqrt{}}{8}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{1437.7536}}{2*4}=\frac{0+\sqrt{1437.7536}}{8}
=\frac{\sqrt{}}{8}
$