The teacher will be very surprised to see your correct solution 😉
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(3)^2 - 4 * (1) * (4) = -7
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
sum
___ ___ 3 I*\/ 7 3 I*\/ 7 - - - ------- + - - + ------- 2 2 2 2
=
-3
product
/ ___\ / ___\ | 3 I*\/ 7 | | 3 I*\/ 7 | |- - - -------|*|- - + -------| \ 2 2 / \ 2 2 /
=
4
4
___ 3 I*\/ 7 x1 = - - - ------- 2 2
___ 3 I*\/ 7 x2 = - - + ------- 2 2
x2 = -3/2 + sqrt(7)*i/2
x1 = -1.5 - 1.3228756555323*i
x2 = -1.5 + 1.3228756555323*i
x2 = -1.5 + 1.3228756555323*i