Maths Olympiad Prep

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Algebra Difficulty 2.1 Junior Find the answer

Given the complex number Z=3−4iZ=3-4i, then ∣Z∣|Z| equals:

Pick one

Solution

Since Z=3−4iZ=3-4i,

then ∣Z∣=32+(−4)2=5|Z|= \sqrt {3^{2}+(-4)^{2}}=5.

Therefore, the correct answer is C\boxed{C}.

This problem is solved directly using the formula for the magnitude of a complex number.

It tests the method of finding the magnitude of a complex number, which is a basic calculation problem.

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Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.