Question

复数Z＝6＋8i分之（3－4i）（1－2i）,解∣z∣＝?

Answer 1

z=(3－4i)(1－2i)/(6+8i)

=(-5-10i)/(6+8i)

=-5(1+2i)(6-8i)/(6+8i)(6-8i)

=-5(22+4i)/100

=-11-2i

∣z∣＝√[(-11)^2+(-2)^2]√125=5√5