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प्रश्न
State whether the expression is meaningful. If not, explain why? If so, state whether it is a vector or a scalar:
`(bar"a".bar"b") xx (bar"c".bar"d")`
उत्तर
This is meaningless because `bar"a".bar"b", bar"c".bar"d"` are scalars and cross product of two scalars is not defined.
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