MAT Flashcards
1
Q
The number of ways to choose r things from n things, order matters
A
n!/(n-r)!
2
Q
Sum of arithmetic series
A
(n/2)(2a+(n-1)d)
3
Q
The number of ways to choose r thing from n things, order doesn’t matter
A
(nCr) = n!/r!(n-r)!
4
Q
Given n independent events each with probability p of success, what’s the probability of exactly r successes?
A
(nCr)p^r (1-p)^(n-r)
5
Q
Three sides, one angle. Area?
A
(1/2)absinC
6
Q
Any arithmetic
A
a(1-r^n)/(1-r) if r =/= 1
7
Q
Cosine rule
A
a^2 = b^2 + c^2 - 2bccosA
8
Q
Sum to infinity geometric series
A
a/(1-r) if |r|<1
9
Q
Any n geometric series
A
a + (n-1)d
10
Q
Sin at 0, 30, 45, 60, 90
A
0, 1/2, sqrt2/2, sqrt3/2, 1
11
Q
Tan for 0, 30, 45, 60, 90
A
0, sqrt3/3, 1, sqrt3, undefined
12
Q
(nCr)
A
n!/r!(n-r)!
13
Q
(x+y)^n
A
(nCr)x^r y^(n-r)
14
Q
Sufficient for, necessary for
A
=>, <=
