Maths Y11

What does P(A n B) mean?

The probability that A and B both occur

What does P(A u B) mean?

The probability that A or B occurs

What is the probability of an event?

Probability measures how likely an event is to happen. It ranges from 0 (impossible) to 1 (certain).

What is the probability of an event NOT happening?

1 - P(x)

What is the probability of one mutually exclusive event or another happening?

Add their probabilities:
P(x or y) = P(x) + P(y)

What is the probability of one not mutually exclusive event or another happening?

P(x or y) = P(x) + P(y) - P(x and y)

What is the probability of independent events both happening?

Multiply their probabilities:
P(x and y) = P(x) x P(y)

What is the probability of dependent events both happening?

P(x and y) = P(x) x P(y given x happened)

What does independent mean in probability?

The outcome of one event does not affect the probability of the other event

What does mutually exclusive mean?

Two events cannot happen at the same time

What is a sample space?

A list or diagram showing all possible outcomes of an experiment

What is a probability tree diagram used for?

To show the possible outcomes of multiple events and calculate their probabilities. Must add to 1

What is the formula for expected frequency?

Number of times experiment is done X probability of event happening

What is the name of this circle theorem and the rule?

Angles on a diameter are equal to 90 (in this case angle PAQ)

What is the name of this circle theorem, the rule and the key point about it?

Angles on a chord are equal (in this case, CAB and DBA are equal.). The key point is that the lines connecting the chords CANNOT go through the middle

What is the name of this circle theorem, the rule and the key point about it?

The angle at the centre is twice the angle at the circumference. It must be at the centre

These are all variations of a circle theorem, but which one?

The angle at the centre is twice the angle at the circumference

What is the name of this circle theorem, the rule and the key point about it?

Opposite angles of a cyclic quadrilateral add up to 180 (in this case, x + y = 180). All 4 corners MUST touch the edge

Two radii form an ________________ if they connect to the endpoints of a chord

Isoceles triangle