Answer:
D
Step-by-step explanation:
Given a quadratic equation in standard form
ax² + bx + c = 0 ( a â 0 ), then the discriminant is
Π= b² - 4ac
⢠If b² - 4ac > 0 then 2 real, irrational roots
⢠If b² - 4ac > 0 and a perfect square then 2 real, rational roots
⢠If b² - 4ac = 0 then 2 equal roots
⢠If b² - 4ac < 0 then 2 complex roots
x² - 3x + 7 = 0 â is in standard form
with a = 1, b = - 3, c = 7 , then
b² - 4ac = (- 3)² - ( 4 à 1 à 7) = 9 - 28 = - 19
Since b² - 4ac < 0 then the equation has 2 complex roots