FINAL EXAM discrete maths Flashcards
1
Q
tautology
A
always true
2
Q
contradiction
A
always false
3
Q
contingency
A
True or False
4
Q
nCr used when?
A
choosing r number of items from a total set of n
5
Q
repetition
A
n!/(r!*r2!)
6
Q
determinant
A
ad-bc
7
Q
A^-1=
A
1/D(d,-b,-c,a]
8
Q
To find matrix solution
A
x=Inverse of A * b (use dot product rule)
9
Q
if D!=0
A
, non singular, has an inverse
10
Q
magnitude of vector v=<a,b>
A
square root of a^2+b^2
11
Q
dot product
A
v.w=(ac)+(bd)
12
Q
dot product (with cos)
A
magnitude of v * magnitude of w* cos(theta)
13
Q
if 2 vectors are orthogonal
A
dot product =0, cos 90 =0 (perpendicular)
14
Q
first order linear difference equation (inhomogoneous)
A
y(n)=a*y(n-1)+b(n)
15
Q
general solution for linear difference
A
a^n * y(0)
