Question Detail

MTH 101 MTH 101 Past Questions Objective Question

Question

Determine the moduli for the complex roots of the quadratic equation given by: \(x^2 - 4x + 13 = 0\)
Options
A \((13, 13)\)
B \((\sqrt{13}, \sqrt{13})\)
Correct Answer
C \((\sqrt{13}, -\sqrt{13})\)
D \((\sqrt{13}, -13)\)
Correct Answer

Option B is the correct answer.

Detailed Explanation

Roots: (x = \frac{4 \pm \sqrt{16-52}}{2} = \frac{4 \pm \sqrt{-36}}{2} = \frac{4 \pm 6i}{2} = 2 \pm 3i). Modulus of each root: (\sqrt{2^2 + 3^2} = \sqrt{4+9} = \sqrt{13}). So both moduli are (\sqrt{13}).

Hint

Find the roots using the quadratic formula, then compute \(\sqrt{a^2+b^2}\).

Question Info