From e8484a6184f60482db41328469475f99e6fd44ff Mon Sep 17 00:00:00 2001
From: Andrew Lorimer <andrew@lorimer.id.au>
Date: Wed, 15 Aug 2018 12:52:57 +1000
Subject: [PATCH 1/1] product & quotient rules

---
 spec/calculus.md | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/spec/calculus.md b/spec/calculus.md
index 503b191..c0056c4 100644
--- a/spec/calculus.md
+++ b/spec/calculus.md
@@ -109,3 +109,17 @@ ${dy \over du} = 7u^6$
 
 $7u^6 \times$
 
+## Product rule
+
+If $f(x)=u(x) \times v(x)$, then $f^\prime (x) = u(x) \times v^\prime(x) + v(x)\times u^\prime(x)$
+
+If $y=uv$, then derivative ${dy \over dx} = u{dv \over dx} + v{du \over dx}$
+
+Surds can be left on denomintaors.
+
+## Quotient rule
+
+If $f(x)={u(x) \over v(x)}$, then $f^\prime(x)={{v(x)u^\prime(x)-u(x)v^\prime(x)} \over [v(x)]^2}$
+
+If $y={u(x) \over v(x)}$, then derivative ${dy \over dx} = {{v{du \over dx} - u{dv \over dx}} \over v^2}$
+
-- 
2.43.2