SCALAR PRODUCT OF VECTOR

[Ana.stasia]

The question:
Calculate the scalar product of vectors a and b if a + 3m -2n, b = m + 4n, where m and n are mutually otrogonal orthoses.

This is how I tried to do it.



Now the last part is 3|m|2 - 8|n|2 would give me the correct solution if m and n equaled 1. Then the result will be -5 which is correct. However why would they be equal to 1? if they even are.

 

[Dr.Peterson]

The question:
Calculate the scalar product of vectors a and b if a = [?] 3m -2n, b = m + 4n, where m and n are mutually otrogonal orthoses.

This is how I tried to do it.

View attachment 23637

Now the last part is 3|m|2 - 8|n|2 would give me the correct solution if m and n equaled 1. Then the result will be -5 which is correct. However why would they be equal to 1? if they even are.

What is the definition of "mutually otrogonal orthoses"? Might that mean "mutually orthogonal unit vectors"?