add matrix left divide text, fix formula matrix_exp_multiply

Author: mitzimorris

src/functions-reference/matrix_operations.Rmd

@@ -1270,12 +1270,14 @@ The right division of B by A; equivalently `B * inverse(A)`
 \index{{\tt \bfseries operator\_left\_div }!{\tt (matrix A, vector b): vector}|hyperpage}
 
 `vector` **`operator\`**`(matrix A, vector b)`<br>\newline
+The left division of A by b; equivalently `inverse(A) * b`
 
 
 <!-- matrix; operator\; (matrix A, matrix B); -->
 \index{{\tt \bfseries operator\_left\_div }!{\tt (matrix A, matrix B): matrix}|hyperpage}
 
 `matrix` **`operator\`**`(matrix A, matrix B)`<br>\newline
+The left division of A by B; equivalently `inverse(A) * B`
 
 
 #### Lower-triangular matrix division functions
@@ -1379,7 +1381,7 @@ The matrix exponential of A
 
 `matrix` **`matrix_exp_multiply`**`(matrix A, matrix B)`<br>\newline
 The multiplication of matrix exponential of A and matrix B;
-algebraically equivalent to the less efficient form `matrix_exp(t * A) * B`.
+algebraically equivalent to the less efficient form `matrix_exp(A) * B`.
 
 <!-- matrix; scale_matrix_exp_multiply; (real t, matrix A, matrix B); -->
 \index{{\tt \bfseries scale\_matrix\_exp\_multiply }!{\tt (real t, matrix A, matrix B): matrix}|hyperpage}