1 files changed, 43 insertions, 7 deletions

diff --git a/README.md b/README.md
index 8cbbaa8..ca5ea65 100644
--- a/README.md
+++ b/README.md
@@ -2,13 +2,49 @@
 
 Simple math expressions calculator
 
-## Sample usage:
-
-    <?php
-    require "vendor/autoload.php";
-    $calculator = new \NXP\MathExecutor();
-    print $calculator->execute("1 + 2 * (2 - (4+10))^2");
-    
 ## Install via Composer
 
 All instructions to install here: https://packagist.org/packages/nxp/math-executor
+
+## Sample usage:
+
+```php
+require "vendor/autoload.php";
+
+$calculator = new \NXP\MathExecutor();
+
+print $calculator->execute("1 + 2 * (2 - (4+10))^2");
+```
+
+## Functions:
+
+Default functions:
+* sin
+* cos
+* tn
+* asin
+* asoc
+* atn
+
+Add custom function to executor:
+```php
+$executor->addFunction('abs', function($arg) {
+    return abs($arg);
+});
+```
+
+## Operators:
+
+Default operators: `+ - * / ^`
+
+## Variables:
+
+You can add own variable to executor:
+
+```php
+$executor->setVars(array(
+    'var1' => 0.15,
+    'var2' => 0.22
+));
+
+$executor->execute("var1 + var2");
\ No newline at end of file