f(2)=-4.9(2)^2+19.6(2)+58.8(2)

Solution for f(2)=-4.9(2)^2+19.6(2)+58.8(2) equation:

f(2)=-4.9(2)^2+19.6(2)+58.8(2)

We move all terms to the left:

f(2)-(-4.9(2)^2+19.6(2)+58.8(2))=0

We add all the numbers together, and all the variables

f^2-54.2336=0

a = 1; b = 0; c = -54.2336;
Δ = b2-4ac
Δ = 02-4·1·(-54.2336)
Δ = 216.9344
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$f_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$f_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$f_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{216.9344}}{2*1}=\frac{0-\sqrt{216.9344}}{2}
=-\frac{\sqrt{}}{2}
$
$f_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{216.9344}}{2*1}=\frac{0+\sqrt{216.9344}}{2}
=\frac{\sqrt{}}{2}
$