dowodzenie
***KIEŁBASA***: 27D wykaż że jeśli:
a1 a2 an
− = − = = −
b1 b2 ... bn
i b1+b2+...+bn≠0
to
a1+a2+...+an a1
−−−−−−−−−− = −
b1+b2+...+bn b1
11 cze 13:34
Bogdan:
| a1 | | a2 | | an | |
| = |
| = ... = |
| |
| b1 | | b2 | | bn | |
| a1 | | a2 | | k1*a1 | | an | | kn−1*a1 | |
| , |
| = |
| , .. , |
| = |
| |
| b1 | | b2 | | k1*b1 | | bn | | kn−1*b1 | |
| a1 + a2 + ... + an | |
| = |
| b1 + b2 + ... + bn | |
| | a1 + k1*a1 + ... + k*n−1*a1 | |
= |
| = |
| | b1 + k1*b1 + ... + k*n−1*b1 | |
| | a1(1 + k1 + ... + kn−1) | | a1 | |
= |
| = |
| |
| | b1(1 + k1 + ... + kn−1) | | b1 | |
11 cze 14:40
AS: Niech an/bn = k dla n = 1,2,3,...
Wówczas a1/b1 = k ⇒ a1 = k*b1
a2/b2 = k ⇒ a2 = k*b2 itd
a1 + a2 + ... + an k*b1 + k*b2 +..+.k*bn k*(b1 + b2 +... + bn) a1
−−−−−−−−−−−−− = −−−−−−−−−−−−−− = −−−−−−−−−−−−−−−− = k = −−−
b1 + b2 + ... + bn b1 + b2 + ... + bn b1 + b2 + ... + bn b1
c.n.d.
11 cze 14:53