diff --git a/education/math/MATH1210 (calc 1)/Derivatives.md b/education/math/MATH1210 (calc 1)/Derivatives.md
index 0bd2185..2660959 100644
--- a/education/math/MATH1210 (calc 1)/Derivatives.md	
+++ b/education/math/MATH1210 (calc 1)/Derivatives.md	
@@ -1,4 +1,4 @@
-A derivative can be used to describe the rate of change for a single point.
+A derivative can be used to describe the rate of change at a single point, or the *instantaneous velocity*.
 
 The formula used to calculate the average rate of change looks like this:
 $$ \dfrac{f(b) - f(a)}{b - a} $$
@@ -6,4 +6,7 @@ Interpreting it, this can be described as the change in $y$ over the change in $
 
 - Speed is always positive
 - Velocity is directional
-- 
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+
+# Line Types
+## Secant Line
+A **Secant Line** connects two points on a graph.
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