Question

If
M2 + M12 + 2 MM1Cosθ = 1, N2 + N12 + 2 NN1Cosθ = 1,
MN + M1N1 + (MN1 + M1N) Cosθ = 0,
Then M2+N2 = ?

Answer 1

Dear visitor.
Unfortunately, the statement of your question is a bit confusing.
It is impossible to solve the assignment because too many variables and only 3 constraints.
Please, give us the details so we could help you.