fix(vectors): fix cross product equation

html/algebra/linear/vectors.html

@@ -125,14 +125,18 @@
         	<div class="title">Cross Product Vector Component Formula</div>
         	<div class="content">
         		\[
-        		    \left( a _ 1 , a _ 2, a _ 3  \right) \times \left( b _ 1, b _ 2, b _ 3 \right) = \left( a _ 2 b _ 2 - a _ 3 b _ 2, a _ 3 b _ 1 - a _ 1 b _ 3, a _ 1 b _ 2 - a _ 2 b _ 1  \right)
+        		    \left( a _ 1 , a _ 2, a _ 3  \right) \times \left( b _ 1, b _ 2, b _ 3 \right) = \left( a _ 3 b _ 2 - a _ 3 b _ 2, a _ 3 b _ 1 - a _ 1 b _ 3, a _ 1 b _ 2 - a _ 2 b _ 1  \right)
         		\]
         	</div>
         	<div class="proof">
 
         	</div>
         </div>
 
+        <p>
+            An easy way to remember this is ab 5 4 3
+        </p>
+
         <div class="definition" id="definition-collinear">
         	<div class="title">Collinear</div>
         	<div class="content">