Răspunsuri

Cel mai inteligent răspuns!
2014-10-12T11:58:27+03:00
1. |X|=x,x>o
       -x,x<0
daca x<0
-x=1 ,x=-1
daca x>0 x=1
solutie
x={-1,1}
2. |x|≤1
|X|= x,daca x>0
       -x ,daca x<o
daca x>0⇒  x≤1 x={1}
daca x<0 ⇒-x≤1 ⇒x≥-1x={-1}
x={-1,1}
3. |x|= x ,daca x>0
          -x ,daca x<0
daca x>0 ⇒ x>1 , x∈(1,+∞)
daca x<0  ⇒-x>1 ,x<-1⇒x∈(-∞,-1)
x∈(-∞,-1)U(1,+∞)