9.81x^2+x-4=0

Solution for 9.81x^2+x-4=0 equation:

9.81x^2+x-4=0

a = 9.81; b = 1; c = -4;
Δ = b2-4ac
Δ = 12-4·9.81·(-4)
Δ = 157.96
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{157.96}}{2*9.81}=\frac{-1-\sqrt{157.96}}{19.62}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{157.96}}{2*9.81}=\frac{-1+\sqrt{157.96}}{19.62}
$