Numbers and definitions Flashcards
Natural numbers are
Positive whole numbers
What is a convergent series?
A geometric sequence that homes in on a number, where you can find the sun to infinity
What are divergent series?
A geometric series where the numbers get infinitely big, there is no sum to infinity. E.g where a = 2 and r= 2
When square rooting, quad rooting etc, what must you put in front of the answer EVERY TIME?!
+-
How do you find the root between a and b?
F(a) and f(b)
If the sign changes there is a root! Check the graph too
What are upper and lower bounds when trying to find out if a value of x is a root?
The numbers that round to that particular value. E.g if x=2.15 Try f(2.145) and f(2.155)
What is the iterative method?
When you rearrange a function so that x is on one side alone (you should end up with a square root).
Then you plug in x0 to find x1, then x1 to find x2 etc
This is to find an APPROXIMATION of a root
What two conditions must be met for the iteration formula to work?
x0 must be close enough to the root
The derivative must be small at a
E.g |f’(x)| < 1
When can the Newton-Raphson formula stop working?
When dy/dx is close to or equal to 0
When interpreting using the trapezium method, what is meant by ordinates?
This is the number of y values, it’s basically n + 1
For example, 4 strips is 5 ordinates