The angle between the two vectors A→=3i^+4j^+5k^ and B→=3i^+4j^−5k^ will be
zero
450
900
1800
A→.B→=(3i^+4j^+5k^).(3i^+4j^−5k^)
=9+16−25=0
or ABcosθ=0 or cosθ=0 or θ=900