Question

Two vectors A and B have precisely equal magnitudes. In order for the magnitude of A+ B to be 110 times larger than the magnitude of A-B , what must be the angle between them?

Answer 1

178.96 degrees

Answer 2

\[\left| A+B \right|=2Acos(\theta)\]
\[\left| A-B \right|=2Asin(\theta)\]
therefore we require \[\tan(\theta)=\frac{ 1 }{ 110 }\]
the angle between A and B is \[180-2\theta\]