The vectors →b and →c are in the direction of north-east and north-west respectively and |→b|=|→c|=4. The magnitude and direction of the vector →d=→c−→b, is
4√2, towards west
Clearly, →b⊥→c,∴→b⋅→c=0
Now, →d=→c−→b ⇒|→d|2=|→c−→b|2
=|→c|2+|→b|2−2→b⋅→c=16+16−0
⇒|→d|=√32=4√2
Now the direction of →b is north east so the direction of −→b will be south west
and since the magnitude of vectors →b and →c is equal →d will lie in the direction of angle bisector of −→b and →c so the direction of →d is west.