A Level Flashcards
What is a rational number?
Can be written as a/b
What is an irrational number?
Can’t be written as a/b
What must happen to an improper algebraic fraction before it is expressed as partial fractions?
Converted to a mixed fraction using algebraic division
How to draw the graph of |f(x)|?
- Sketch y=f(x)
- Reflect any parts where f(x)<0 in the x-axis
- Delete the parts below x-axis
How to draw graph of f(|x|)?
Sketch graph of y=f(x) where f(x)>0
Reflect this in y-axis
Formula for arithmetic sequence?
U=a+(n-1)d
Formula for geometric sequence?
U=ar^(n-1)
What makes a geometric sequence convergent?
|r|<1
What makes a sequence periodic and what is the order of a periodic sequence?
If the terms repeat in a cycle. The order is how many terms before the same term repeats again
When is a binomial expansion valid?
When |x|<1
What makes approximations based on the binomial expansion more accurate?
- Using more terms of the expansion
- The values of x substituted into the expansionare closer to 0
How many degrees is pi radians?
180 degrees
