Answer: 4c+1.
- A 4c
- B 4c+1
- C 4c-1
- D c+4
Correct answer: B. 4c+1
Explanation: alpha - beta = 1. (alpha-beta)² = (alpha+beta)² - 4 alpha×beta = b² - 4c = 1. So b² = 4c + 1.
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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