Study Flashcards
How do you find the HCF of two numbers?
You fet the prime factorization of the two numbers and see which primes they have in common. Then multiply the primes to get the HCF!
How do you find the LCM of two numbers?
You get the prime factorization and see which numbers repeat and write those down and multiply them. Example: 20 (2,2,5) and 84 (2,2,3,7). To get the LCM we do 2 x 2 x 3 x 5 x 7 which is 420.
What are the formulas for volume and perimeter of a regular polygon?
Area= (n x s x a)/2
Perimeter= n x s
n= Nuber of sides s= Side length a= Apothem
What is similarity in mathematics?
Two shapes are similar if their angles are the same and the sides share a scale factor (1:2 for example). They do not have to be the same size though.
What is congruence in mathematics?
Two shapes are congruent if they have the same angles and sides but not necerarily the same position or rotation.
What are arithmetic sequences?
Sequences that increase linearly. They increase or decrease by adding or substracting one consistant ammount.
They come in the form of Un= an + b
For example, 1,4,7,10,13,16,18 is represented as Un= 3n - 2
What are quadratic sequences? How do you solve them?
They are sequences that have two differences and get exponentially higher or lower.
Sequence: 1,4,9,16,23,32,43
First difference: 3,5,7,9,11
Second difference: 2, 2, 2, 2
a + b + c = 1
3a + b = 3
2a = 2
a= 1 b= 0 c= 0
Un= n^2
What are cubic sequences? How do you solve them?
The same as cubic but bigger.
Sequence: 6, 7, 11, 20, 68
First difference:1, 4, 19, 48
Second difference: 3, 15, 27
Third difference: 12,12
a+b+c+d = 6
7a + 3b + c = 1
12a + 2b = 3
6a = 12
What is the system of equations for cubic sequences?
a+b+c+d
7a + 3b + c
12a + 2b
6a
What is the system of equations for quadratic sequences?
a + b + c = 1
3a + b = 3
2a = 2
What are geometric sequences?
They are sequences that use powers to grow or decrease.
They use the formula: Un= u1 * r ^ (n-1)
u1= The first therm of the sequence
r= By what number you multiplied to get to the second digit.
What is the formula for the sine rule?
a/sinA= b/sineB= c/sinC (sides)
sinA/a=sinB/b=sinC/c (angles)
When do we use the sine rule?
When we have two angles and one side or two sides and 1 undetermined angle.
What is the formula for the cosine rule?
a^2= b^2 + c^2 - 2ab * cosA
cosA=- (b^2 + c^2-a^2)/ 2ab
When do we use the cosine rule?
When we have 3 sides or two sides and an angle.
