Answer: Not real (imaginary).
- A Real and distinct
- B Real and equal
- C Not real (imaginary)
- D Rational
Correct answer: C. Not real (imaginary)
Explanation: When D < 0, sqrt(D) is imaginary. The roots are complex conjugates (not real).
A complex number z = a+ib is plotted as a point (or vector from the origin) on the Argand plane, with the real part along the horizontal axis and the imaginary part along the vertical; its modulus |z| is the vector's length, and its argument θ is the angle from the positive real axis.
Concept context
Complex numbers in a+ib form, modulus, argument, polar form, cube roots of unity, and quadratic equations with complex roots
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