The length of the median through A of the ∆ABC ,whose sides are AB→=−3i^+4k^ and AC→=5i^−2j^+4k^ is
14
18
29
5
AB→+AC→=2AD→∴ AD→=12{(−3i^+4k^)+(5i^−2j^+4k^)}=i^−j^+4k^
Length of AD=1+1+16=18