DirectSum.md (344B)
1 # Direct Sum 2 3 **Source:** Linear Algebra Done Right 4 5 **Chapter:** 1 6 7 **Definition:** A direct sum is a sum of two vector spaces that are disjoint except for the zero vector. 8 9 This can also be stated as each element being writeable as a **unique** combination (sum) of vectors in the vector spaces. This notion leads to a good way to test this.