Algebra Flashcards
1
Q
Permutari
A
n!
2
Q
Aranjamente
A
n!/ (n-k)!
3
Q
Combinari
A
n!/ k!(n-k)!
4
Q
Lege asociativa
A
(x ∘ y) ∘ x = x (y ∘ z)
5
Q
Lege comutativa
A
x ∘ y = y ∘ x
6
Q
Legea are element neutru
A
x ∘ e = e ∘ x = x
7
Q
Legea are element simetrizabil
A
x ∘ x’ = x’ ∘ x = e
8
Q
Legea are element absorbant
A
x ∘ a = a ∘ x = a
9
Q
Termenul general intr-o progresie geometrica
A
b(n) = b1 x q^(n-1)
10
Q
Suma n termeni intr-o progresie geometrica
A
S(n) = b1 (q^n - 1) / q-1
11
Q
Termen general intr-o progresie aritmetica
A
a(n) = a1 + r(n-1)
12
Q
Suma n termeni intr-o progresie aritmetica
A
S(n) = n(a1 + an) / 2
13
Q
Coordonatele varfului parabolei
A
-b/2a si -Δ/4a
14
Q
Axa de simetrie a unei parabole
A
x = -b/2a
15
Q
Relatiile lui Viette
A
- x1 + x2 = -b/a
2. x1 ⋅ x2 = c/a
