[backport] doc/tut3.rst: Fix typo in Introduction (#12607) [ci skip]

Derivative of `b*pow(x, 2)` is `2*b*x`, while old version had `2*a*x`
nim-lang · Nov 6, 2019 · 5ccbf7e · 5ccbf7e
1 parent 61889c6
commit 5ccbf7e
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/doc/tut3.rst b/doc/tut3.rst
@@ -28,7 +28,7 @@ Examples of things that can be implemented in macros:
 
 * Symbolic differentiation of an expression.
   ``diff(a*pow(x,3) + b*pow(x,2) + c*x + d, x)`` is converted to
-  ``3*a*pow(x,2) + 2*a*x + c``
+  ``3*a*pow(x,2) + 2*b*x + c``
 
 
 Macro Arguments