The teacher will be very surprised to see your correct solution 😉
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(1)^2 - 4 * (1) * (-3) = 13
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
____ 1 \/ 13 x1 = - - + ------ 2 2
____ 1 \/ 13 x2 = - - - ------ 2 2
x2 = -sqrt(13)/2 - 1/2
sum
____ ____ 1 \/ 13 1 \/ 13 - - + ------ + - - - ------ 2 2 2 2
=
-1
product
/ ____\ / ____\ | 1 \/ 13 | | 1 \/ 13 | |- - + ------|*|- - - ------| \ 2 2 / \ 2 2 /
=
-3
-3