diff --git a/unnecessarymath.py b/unnecessarymath.py
index 1cfa9db80c857c8128cb3dc8d9d06d5a01161ea8..14f404be0bc2d842a193d12458639d4383813038 100644
--- a/unnecessarymath.py
+++ b/unnecessarymath.py
@@ -3,7 +3,15 @@
 import numpy as np
 
 def sqrt(x):
-    """Evaluate the square root of a non-negative number"""
+    """
+    Evaluate the square root of a non-negative number
+
+    >>> sqrt(4)
+    2.0
+
+    >>> sqrt(1.)
+    1.0
+    """
     return np.sqrt(x)
 
 def square(x):