Complex Addition/Examples/Travel 2/Mistake

Source Work

1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.)

Chapter $1$: Complex Numbers

Supplementary Problems: Polar Form of Complex Numbers: $85$

Mistake

An airplane travels $150 \, \mathrm {km}$ southeast, $100 \, \mathrm {km}$ due west, $225 \, \mathrm {km}$ $30 \degrees$ north of east, and then $323 \, \mathrm {km}$ northeast. Determine ... how far and in what direction it is from its starting point.

Ans. $\ 375 \, \mathrm {km}$, $23 \degrees$ north of east (approx.)

Correction

The correct solution is:

$490$ kilometres in a direction $28.7 \degrees$ north of east from its starting point.

Sources

• 1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.) ... (previous) ... (next): $1$: Complex Numbers: Supplementary Problems: Polar Form of Complex Numbers: $85 \ \text {(b)}$