Answer: One repeated real root.
- A Two distinct real roots
- B One repeated real root
- C Two imaginary roots
- D No roots
Correct answer: B. One repeated real root
Explanation: When D = 0, the quadratic has exactly one repeated real root: x = -b/2a.
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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