If the quadratic formula is used to solve 2x 2 - 3x - 1 = 0, what are the solutions?

Hello : 
the discriminat of each quadratic equation : ax²+bx+c=0 (a ≠ 0) is :
Δ = b² -4ac
1 )  Δ > 0  the equation has two reals solutions : x =  (-b±√Δ)/2a
2 ) Δ = 0 : one solution : x = -b/2a
3 ) Δ < 0 : no reals solutions
in this exercice :   2x ² - 3x - 1 = 0a =2        b =-3        c =-1
calculate : Δ

7.666270253x10 raised to the 18th power