Algebra

Question 1

Permutari

Answer 1

n!

Question 2

Aranjamente

Answer 2

n!/ (n-k)!

Question 3

Combinari

Answer 3

n!/ k!(n-k)!

Question 4

Lege asociativa

Answer 4

(x ∘ y) ∘ x = x (y ∘ z)

Question 5

Lege comutativa

Answer 5

x ∘ y = y ∘ x

Question 6

Legea are element neutru

Answer 6

x ∘ e = e ∘ x = x

Question 7

Legea are element simetrizabil

Answer 7

x ∘ x’ = x’ ∘ x = e

Question 8

Legea are element absorbant

Answer 8

x ∘ a = a ∘ x = a

Question 9

Termenul general intr-o progresie geometrica

Answer 9

b(n) = b1 x q^(n-1)

Question 10

Suma n termeni intr-o progresie geometrica

Answer 10

S(n) = b1 (q^n - 1) / q-1

Question 11

Termen general intr-o progresie aritmetica

Answer 11

a(n) = a1 + r(n-1)

Question 12

Suma n termeni intr-o progresie aritmetica

Answer 12

S(n) = n(a1 + an) / 2

Question 13

Coordonatele varfului parabolei

Answer 13

-b/2a si -Δ/4a

Question 14

Axa de simetrie a unei parabole

Answer 14

x = -b/2a

Question 15

Relatiile lui Viette

Answer 15

1. x1 + x2 = -b/a

2. x1 ⋅ x2 = c/a