From 5325bb45e27fd76e62f77ac9e361315167b0c4ae Mon Sep 17 00:00:00 2001
From: zleyyij <75810274+zleyyij@users.noreply.github.com>
Date: Mon, 28 Oct 2024 11:05:14 -0600
Subject: [PATCH] vault backup: 2024-10-28 11:05:14

---
 .../Double and Half Angle Identities.md              | 12 +++++++++++-
 1 file changed, 11 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 122ab8f..a72541b 100644
--- a/education/math/MATH1060 (trig)/Double and Half Angle Identities.md	
+++ b/education/math/MATH1060 (trig)/Double and Half Angle Identities.md	
@@ -1,3 +1,7 @@
+To solve for a double or half angle identity:
+1. Draw a triangle
+2. Choose an identity to use
+3. Substitute into formula
 # Double Angle Identities
 Sine:
 $$ \sin(2\theta) = 2\sin\theta\cos\theta $$
@@ -20,4 +24,10 @@ $$ \sin(\frac{\theta}{2}) = \pm\sqrt{\frac{1-\cos\theta}{2}} $$
 Cosine:
 $$ \cos(\frac{\theta}{2}) = \pm \sqrt{\frac{1 + \cos\theta}{2}} $$
 Tangent:
-$$ \tan(\frac{\theta}{2}) = \pm\sqrt{\frac{1-\cos\theta}{1 + \cos\theta}} $$
\ No newline at end of file
+$$
+\begin{matrix}
+\tan(\dfrac{\theta}{2}) = \pm\sqrt{\dfrac{1-\cos\theta}{1 + \cos\theta}}\\
+= \dfrac{\sin\theta}{1 + \cos\theta}\\
+= \dfrac{1 - cos\theta}{\sin\theta}
+\end{matrix}
+$$
\ No newline at end of file