Answer: 25/24.
- A 25/24
- B -25/24
- C 25/12
- D -13/12
Correct answer: A. 25/24
Explanation: alpha+beta = -1/2, alpha×beta = -3. alpha/beta + beta/alpha = [(alpha+beta)² - 2 alpha×beta]/(alpha×beta) = [1/4+6]/(-3) = (25/4)/(-3) = -25/12.
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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