R Flashcards
Quadratic Formula
x = -b +/- √(b^2 - 4ac)
/ 2a
If b^2 - 4ac is equal to 0, how many solutions?
One solution.
If b^2 - 4ac is positive, how many solutions?
Two solutions.
If b^2 - 4ac is negative, how many solutions?
No solution.
An integer is divisible by 3 if the sum of the integer’s digits…
is divisible by 3.
A number is divisible by 4 if
it’s simply divisible by 2 twice, or
if the last two digits are divisible by 4.
An integer is divisible by 6 if
it’s divisible by both 2, and 3 (sum of digits are divisible by 3).
An integer is divisible by 8 if
the last 3 digits are divisible by 8 (divisible by 2 three times)
An integer is divisible by 9 if
the sum of the integer’s digits is divisible by 9
Factor Foundation Rule
If a is a factor of b, and b is a factor of c, then a is definitely a factor of c.
Even x even
Even
Even x Odd
Even
Odd x Odd
Odd
Even + Even
Even
Even + Odd
Odd
Odd + Odd
Even
3!
6
4!
24
5!
120
6!
720
7!
5040
Multiple + non-multiple =
Non-multiple
Non-multiple + non-multiple =
Multiple OR non-multiple
Within the prime circles: GCF is the product of
all the primes in the shared region only.
Within the prime circles: LCM is the product of
all the primes in the diagram (just count once the ones on shared region).
Within prime column: how to compute for GCF:
Take the prime bases with smallest count of power and multiply
Within prime column: how to compute for LCM:
Take the prime bases with the highest count of power and multiply.
How many different prime factors means
How many unique prime factors
How many total prime factors (length) means
How many total prime factors (the length).
How many total factors means
How many factor pairs
Perfect square integers have how many total factors?
Odd number of total factors.
N! is a multiple of
all the numbers from 1 to N
