Trigonometry

what is sin(x) equal to

sin(x) = sin(180-x)

Formula for the sine rule

Sin(A)/a = Sin(B)/b or a/sin(A) = b/sin(B)

What do the capital letters represent?

The angle

What do the lower case letters represent?

the sides

When is the sine rule used?

when you either have:

-two angles and one side or

-two sides and one angle

When is the cosine rule used?

When you either have:

-three sides given and want to find an angle

-Have two sides and an angle given between them (like a sandwich)

What is the cosine formula to find a side?

a²=b²₊c²-2bc×cos(A)

What is the cosine formula to find an angle?

Cos(A) = b²+c²-a²/2bc

How do you find the area of a non-right angled triangle?

Area = ½ab sin(c)

a and b are the sides given

c is the angle given

What is the relationship between A and a?

A is the angle and a is the side opposite A

What are vectors?

they have magnitude (size) and direction

What does the top number mean in column vectors?

+ is right

- is left

What does the bottom number mean in column vectors?

+ means up

- means down

How do you find the vectors between two points?

A = (x₁, y₁)

B = (x₂, y₂)

AB→=(x₂-x₁/y₂, y₁)

How do you find the length of a vector?

√a²+b² (a/b)

Parallel vectors

two vectors are parallel is one is a multiple of the other

what does AB→ mean

it means the vector from point A to B. it shows the direction and represents the movement needed to get from the first point to the second

Vector addition

a→ + b→means go along vector a then go along vector b

- it means follow the direction

Vector subtraction

a→-d→ means go along vector a then go backwards along vector d

-it means to travel in the opposite direction that is shown

Vectors on a straight line

points are on a straight line if they have parallel vectors and have a point in common