study guides for every class

that actually explain what's on your next test

Complement of an event

from class:

Algebra and Trigonometry

Definition

The complement of an event is the set of all outcomes in the sample space that are not part of the event. It is denoted as $E'$ or $E^c$ for an event $E$.

congrats on reading the definition of complement of an event. now let's actually learn it.

ok, let's learn stuff

5 Must Know Facts For Your Next Test

  1. The probability of the complement of an event is given by $P(E') = 1 - P(E)$.
  2. If an event $E$ is certain, then its complement has a probability of zero.
  3. If two events are mutually exclusive and exhaustive, their probabilities sum to one.
  4. The complement rule can simplify calculations, especially when it is easier to calculate the probability of the complement rather than the event itself.
  5. The union of an event and its complement covers the entire sample space.

Review Questions

  • What is the formula to find the probability of the complement of an event?
  • How does knowing the complement help in calculating probabilities?
  • Explain what it means for two events to be mutually exclusive and exhaustive.
© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.
Glossary
Guides