How do you know if a set of vectors are orthogonal?
We know two vectors are orthogonal if their dot product is zero.
Similarly, a set of vectors A is orthonormal if every vector in A has magnitude one and the set of vectors are mutually orthogonal.
How do you know if two vectors are orthogonal?
How do you know if a determinant is zero?
How do you know if a hyperbola is open?