diff --git a/education/math/MATH1210 (calc 1)/Derivatives.md b/education/math/MATH1210 (calc 1)/Derivatives.md
index 439e1a5..ad4e4be 100644
--- a/education/math/MATH1210 (calc 1)/Derivatives.md	
+++ b/education/math/MATH1210 (calc 1)/Derivatives.md	
@@ -17,7 +17,8 @@ The above formula can be used to find the *derivative*. This may also be referre
 
 # Point Slope Formula (Review)
 $$  y - y_1 = m(x-x_1) $$
-Given that $m = f'(a)
+Given that $m = f'(a)$ and that $(x_1, y_1) = (a, f(a))$, you get the equation:
+$$ y - f(a) = f'(a)(x - a)
 
 # Line Types
 ## Secant Line