Definition Suppose that S:V→W is a function A inverse of S is T:W→V s.t ∀v∈V,TS(v)=v ∀w∈W,ST(w)=w Uniqueness Definition T invertible ⟺∀b,Tv=b has a Unique Solution Theorems Injectivity Surjectivity and Inverses Determinants and Invertiblity Theorem Invertibility and Eigenvalues Linear Map Inverses are Unique Linear Map Inverses are Linear