We have |12 - 38i| = |18(4 - 3i)| = 18|4-3i| = 184^2 +(-3)^2 = 58.

jmc

algebra junior

Problem

Evaluate

\frac{1}{2} - \frac{3}{8} i

Solution

We have

\frac{1}{2} - \frac{3}{8} i = \frac{1}{8} (4 - 3 i) = \frac{1}{8} ∣4 - 3 i ∣ = \frac{1}{8} 4^{2} + (- 3)^{2} = \frac{5}{8} .

Final answer

\frac58