1 files changed, 2 insertions, 0 deletions
diff --git a/NEWS b/NEWS
index 4e344227bb..acf414caa2 100644
--- a/NEWS
+++ b/NEWS
@@ -31,6 +31,8 @@ with all sufficient information, see the ChangeLog file.
   * New methods:
     * Matrix#first_minor(row, column) returns the submatrix obtained
       by deleting the specified row and column.
+    * Matrix#cofactor(row, column) returns the (row, column) cofactor
+      which is obtained by multiplying the first minor by (-1)**(row + column).
 
 === Core classes compatibility issues (excluding feature bug fixes)