-4.905y^2+6y-1=0

Solution for -4.905y^2+6y-1=0 equation:

-4.905y^2+6y-1=0

a = -4.905; b = 6; c = -1;
Δ = b2-4ac
Δ = 62-4·(-4.905)·(-1)
Δ = 16.38
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-\sqrt{16.38}}{2*-4.905}=\frac{-6-\sqrt{16.38}}{-9.81}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+\sqrt{16.38}}{2*-4.905}=\frac{-6+\sqrt{16.38}}{-9.81}
$