Formule la algebra

Algebra

(a+b)(a-b)=a2 - b2

(a+b) 2 =a2 + 2ab + b2  EMBED Equation.3 


(a-b) 2 =a2 - 2ab + b2

Numere reale conjugale:
 EMBED Equation.3 
 are conjugatul EMBED Equation.3 


2X+7X=9X
2X-5X=-3X

 2 coeficient
2X
X parte literala

2x –monom
2x+4y –binom POLInoame
2x+4y-7 –tirnom



(a+b+c) 2 = a 2 +b 2 +c 2 = 2ab+2ac+2bc

(a+b)(x+y)=ax+ay+bx+by

ax + ay + bx + by = a(x+y)+b(x+y)=(x+y)(a+b)
Daca ab=0 => a=0 sau b=0
Daca |x|=3 => x=3 sau x=-3
Daca X2 =25 =>  EMBED Equation.3 
X=5 sauX=-5 => EMBED Equation.3 


! Pentru a rezolva o ecuatie de gradul 2 procedam astfel:
1) Trecem totzi termeni in membrul stang
2) Descompunem in factori membrul stang
3) Egalam fiecare factor cu 0 si gasim radacinile


Formula de rezolvare a ecuatie de gradul 2

ax 2 +bx +c =0

a, b, c coeficienti
calculeaza discriminantul
?=b2 -4 ac
3)Aflam  EMBED Equation.3 




2x2 - 7x+ 5=0
a=2 b=-7 c=5
?= 49 -40 =9 ? 0
 EMBED Equation.3 
= EMBED Equation.3 


 EMBED Equation.3 
= EMBED Equation.3 

Daca A(x; y)
B(x2; y2) atunci mij AB EMBED Equation.3 


Dependenta funcionala:

Se numeste dependenta funcioonala intre 2 multimi nevide A,Bo corespondenta intre elementele luiA si elementele lui b care face ca la orice element din a sa-I corespunda un isngur element in B.

A=domeniu de definitie
B=codomeniu(multimea in care dependenta
functonala ia valori)
Legea de corespondenta este al 3-lea element

Probabilitatea

Problema: Un pachet de carti are 52 carti.
Aflati probabilit...