Document use of / in LinearAlgebra

stdlib/LinearAlgebra/docs/src/index.md

@@ -315,6 +315,7 @@ Other sparse solvers are available as Julia packages.
 ```@docs
 Base.:*(::AbstractMatrix, ::AbstractMatrix)
 Base.:\(::AbstractMatrix, ::AbstractVecOrMat)
+Base.:/(::AbstractVecOrMat, ::AbstractVecOrMat)
 LinearAlgebra.SingularException
 LinearAlgebra.PosDefException
 LinearAlgebra.ZeroPivotException

stdlib/LinearAlgebra/src/generic.jl

@@ -1112,6 +1112,31 @@ function (\)(A::AbstractMatrix, B::AbstractVecOrMat)
 end
 
 (\)(a::AbstractVector, b::AbstractArray) = pinv(a) * b
+
+"""
+    A / B
+
+Matrix right-division: `A / B` is equivalent to `(A' \ B')'` where [`\`](@ref) is the left-division operator.
+For square matrices, the result `X` is such that `A == X*B`.
+
+See also: [`rdiv!`](@ref).
+
+# Examples
+```jldoctest
+julia> X = Float64[1 4 2; 3 4 2; 8 7 1]; B = Float64[1 4 5; 3 9 2];
+
+julia> A = B/X
+2×3 Matrix{Float64}:
+ -0.65   3.75  -1.2
+  3.25  -2.75   1.0
+
+julia> A ≈ B*pinv(X)
+true  
+
+julia> A*X ≈ B
+true
+```
+"""
 function (/)(A::AbstractVecOrMat, B::AbstractVecOrMat)
     size(A,2) != size(B,2) && throw(DimensionMismatch("Both inputs should have the same number of columns"))
     return copy(adjoint(adjoint(B) \ adjoint(A)))