diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58b399f..5356ad9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Random mode modified
 ## [0.8] - 2022-06-01
 ### Added
 - `INVALID_COLOR_TYPE_ERROR` error
diff --git a/samila/functions.py b/samila/functions.py
index 139e82d..dfb976f 100644
--- a/samila/functions.py
+++ b/samila/functions.py
@@ -27,17 +27,22 @@ def random_equation_gen():
 
     :return: equation as str
     """
-    num_elements = random.randint(2, len(ELEMENTS_LIST) + 3)
+    num_elements = random.randint(1, len(ELEMENTS_LIST))
     result = ""
     index = 1
     random_coef = random.choice(RANDOM_COEF_LIST)
     while(index <= num_elements):
         argument = random.choice(ARGUMENTS_LIST)
+        if random.randint(0, 1) == 1:
+            argument = random.choice(ELEMENTS_LIST).format(
+                random_coef, argument)
         result = result + \
             random.choice(ELEMENTS_LIST).format(random_coef, argument)
         if index < num_elements:
             result = result + random.choice(OPERATORS_LIST)
         index = index + 1
+    if random.randint(0, 1) == 1:
+        result = random.choice(ELEMENTS_LIST).format(random_coef, result)
     return result
 
 
@@ -106,7 +111,7 @@ def is_valid_color(color):
     :type color: any format
     :return: result as bool
     """
-    if color == None:
+    if color is None:
         return True
     try:
         _ = matplotlib.colors.to_hex(color)
diff --git a/samila/params.py b/samila/params.py
index ec07031..d6f362f 100644
--- a/samila/params.py
+++ b/samila/params.py
@@ -98,6 +98,8 @@ ARGUMENTS_LIST = [
     "y**2",
     "(x**2)*y",
     "(y**2)*x",
+    "(y**2)+(x**2)",
+    "(y**2)-(x**2)",
     "(x**2)*(y**3)",
     "(x**3)*(y**2)",
     "x*(y**3)",