中等MATH-ALGE-003
What is the discriminant of 2x^2 + 3x + 5 = 0?
A. −31✓ 答案
B. −11
C. 31
D. 49
解說
Δ = b^2 − 4ac = 9 − 4(2)(5) = 9 − 40 = −31. The equation has no real root. The value 31 drops the minus sign in front of 4ac.
Δ = b^2 − 4ac = 9 − 4(2)(5) = 9 − 40 = −31. The equation has no real root. The value 31 drops the minus sign in front of 4ac.