- 4j² + 3j - 28 =0
It's quadratic equation of the form ax² + bx + c, where a = -4, b=3 and c =- 28.
The discriminent Δ = b² - 4.a.c
Δ = 3² - 4(-4)(-28)
Δ = -439
If Δ ≥ 0 there are either 2 roots or one double if = 0)
if Δ< 0, there are no real roots (but 2 imaginary roots)
Since Δ < 0, then there is no real roots
