From c2b24f4ad8cfe8992743ecfedb37aa9b9630beb5 Mon Sep 17 00:00:00 2001 From: eggy Date: Tue, 9 Mar 2021 18:19:04 -0500 Subject: [PATCH] math: add conditional probability --- docs/mcv4u7.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/docs/mcv4u7.md b/docs/mcv4u7.md index fc65772..3ad4ba8 100644 --- a/docs/mcv4u7.md +++ b/docs/mcv4u7.md @@ -186,9 +186,17 @@ $$ Events $A$ and $B$ are **exhaustive** if their union includes all possible outcomes in the sample space: $A\cup B=U$. $$P(A\cup B)=1$$ -The **principle of inclusion and exclusion** forms a general rule for the union between two sets: +The **principle of inclusion and exclusion** forms a general rule for the union between two *independent* events: $$P(A\cup B)=P(A)+P(B)-P(A\cap B)$$ +### Conditional probability + +A vertical bar is used between two events to denote that the event on the left occurs knowing that the right has already occurred. +$$P(A|B) = \frac{P(A\cap B)}{P(B)}$$ + +!!! example + $P(A|B)$ is the probability of event $A$ given $B$ has occurred. + ## Resources - [IB Math Analysis and Approaches Syllabus](/resources/g11/ib-math-syllabus.pdf)