Formulae Flashcards
1
Q
Surface area of a sphere
A
4 πr^2
2
Q
Curved area of a cone
A
πrl
L= slant height
3
Q
Nth term of arithmetic sequence
A
Un= a+(n-1)d
4
Q
Sum of an arithmetic sequence
A
Sn=0.5n(a+l)=0.5n(2a+(n-1)d)
5
Q
Nth term of geometric sequence
A
Un=ar^(n-1)
6
Q
Sum of a geometric sequence
A
Sn=a(1-r^n) / (1-r)
7
Q
Sum to infinity of a geometric sequence
A
S=a / (1-r)
for r<1
8
Q
Cosine rule
A
a ^2 = b ^2 + c ^2 - 2bc cosA
9
Q
Sine rule
A
a/sinA = b/sinB
10
Q
Area of a triangle
A
0.5ab sinC
11
Q
N choose R
A
n! / r! (n-r)!
12
Q
Trapezium rule
A
0.5h ( (y0 + y1) + 2(y1 + y2 + y3…… + yn-1) )
13
Q
Trapezium rule h=
A
h=(b-a) / n
