Answer: y = 3.
- A x = 3
- B y = 3
- C x² + y² = 9
- D y = 3x
Correct answer: B. y = 3
Explanation: Im(z) = b = 3 means the imaginary part is 3. This is the horizontal line y = 3.
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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