Homework Statement
For what values of k is (scalar product of vectors a and b) = a_{1}b_{1}-a_{1}b_{2}-a_{2}b_{1}+ka_{2}b_{2} a valid scalar product?
The vectors a and b are defined as:
a = a_{1}e_{1} + a_{2}e_{2}
b = b_{1}e_{1} + b_{2}e_{2}
where e_{1} and e_{2} are unit vectors...