Search found 8 matches
- Fri Nov 21, 2008 4:33 pm
- Forum: Clasa a 11-a
- Topic: Determinanti, matrici
- Replies: 4
- Views: 809
Determinanti, matrici
1. Fie o matrice A\in \mathcal{M}_{(2,3)}(\mathbb R ) , A = \begin{pmatrix}1 & 2 & 3 \\x & y & z\end{pmatrix}; si Det A\cdot A^T = 0 Aratati ca \frac{x}{1}=\frac{y}{2}=\frac{z}{3} 2. A = \begin{pmatrix}a&b&c\\c&a&b\\b&c&a\end{pmatrix}; a,b,c\in(\mathbb R); a^2...
- Thu Oct 23, 2008 7:04 pm
- Forum: Clasa a 11-a
- Topic: Limite de siruri (presupune o suma)
- Replies: 7
- Views: 1319
- Thu Oct 23, 2008 6:17 pm
- Forum: Clasa a 11-a
- Topic: Suma simpla
- Replies: 4
- Views: 773
- Thu Oct 23, 2008 6:02 pm
- Forum: Clasa a 11-a
- Topic: Suma simpla
- Replies: 4
- Views: 773
- Thu Oct 23, 2008 5:40 pm
- Forum: Clasa a 11-a
- Topic: Limite de siruri (presupune o suma)
- Replies: 7
- Views: 1319
- Thu Oct 23, 2008 4:28 pm
- Forum: Clasa a 11-a
- Topic: Limite de siruri (presupune o suma)
- Replies: 7
- Views: 1319
- Thu Oct 23, 2008 3:57 pm
- Forum: Clasa a 11-a
- Topic: Suma simpla
- Replies: 4
- Views: 773
Suma simpla
Sa se calculeze suma din \( \frac{1*1!+2*2!+3*3!+...+n!*n}{-1+(n+1)!} \).
Multumesc.
Multumesc.
- Thu Oct 23, 2008 3:43 pm
- Forum: Clasa a 11-a
- Topic: Limite de siruri (presupune o suma)
- Replies: 7
- Views: 1319
Limite de siruri (presupune o suma)
1. Sa se calculeze limita sirului a_n=\frac{1\cdot 1!+2\cdot 2!+3\cdot 3!+\dots+n\cdot n!}{-1+(n+1)!} . 2. Sa se determine numerele naturale a, b pentru care \lim(\frac{a\cdot n^2+n+a}{n^2+3})^{\frac{b\cdot n+2}{n+3}}=16 . La 1 e necesar doar suma sa o aflu ca limita o pot afla foarte usor. Multumesc!