From 75074fe98d2574c043aa718df4091e5ab644de25 Mon Sep 17 00:00:00 2001
From: zleyyij <75810274+zleyyij@users.noreply.github.com>
Date: Mon, 28 Oct 2024 10:50:14 -0600
Subject: [PATCH] vault backup: 2024-10-28 10:50:14

---
 .../Double and Half Angle Identities.md                | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/education/math/MATH1060 (trig)/Double and Half Angle Identities.md b/education/math/MATH1060 (trig)/Double and Half Angle Identities.md
index f626c4a..c89557f 100644
--- a/education/math/MATH1060 (trig)/Double and Half Angle Identities.md	
+++ b/education/math/MATH1060 (trig)/Double and Half Angle Identities.md	
@@ -1,2 +1,10 @@
+# Double Angle Identities
 $$ \sin(2\theta) = 2\sin\theta\cos\theta $$
-$$ \cos(2\theta) = \cos^2\theta - \sin^2
\ No newline at end of file
+$$
+\begin{matrix}
+\cos(2\theta) = \cos^2\theta - \sin^2\theta\\
+= 1 - 2sin^2\theta\\
+= 2cos^2\theta - 1\\
+\end{matrix}
+$$
+$$ \tan(2\theta) = \dfrac{2\tan\theta}{1-\tan^2\theta}$$
\ No newline at end of file