Functii -introducere

 $f:\left\{1,3,5,7,9\right\}\rightarrow\left\{2,6,10,14,18\right\},\ f\left(x\right)=2x$  Domeniul de definitie al functiei este

•  $\left\{1,3,5,7,9\right\}$  
  

•  $\left\{2,6,10,14,18\right\}$  
  

Codomeniul functiei     

 

•  $\left\{-1,0,1,2\right\}$  

•  $\left\{2,3,0,3\right\}$  

•  $\left\{0,2,3\right\}$  

 $f:\left\{-2,-\frac{1}{3},0,1,\frac{2}{3}\right\}\rightarrow\left\{-4,1,2,3,4,5\right\},f\left(x\right)=3x+2$  Imaginea functiei este

•  $\left\{-4,1,2,3,4,5\right\}$  

•  $\left\{-2,-\frac{1}{3},0,1,\frac{2}{3}\right\}$  

•  $\left\{-4,1,2,4,5\right\}$  

Corespondenta urmatoare este o functie?  $f:\left\{-2,3,5,6\right\}\rightarrow\left\{1,3,4\right\},\ f\left(-2\right)=3,f\left(3\right)=4,f\left(5\right)=1$  

• Nu

• Da

Corespondenta urmatoare este functie?

 $f:\left\{-2,0,1,\ 2\right\}\rightarrow\left\{-3,1,3,4\right\},\ f\left(-2\right)=1,\ f\left(0\right)=-3,\ f\left(1\right)=4,\ f\left(-2\right)=3$  

• Da

• Nu

 $f:\left\{0,1,2,3,\right\}\rightarrow\left\{0,3,6,9\right\},\ f\left(x\right)=3x.\$  Imaginea lui 2 este

• 0

• 3

• 6

• 9

 $f:\left\{2,4,6,8,10\right\}\rightarrow\left\{1,2,3,4,5\right\},\ f\left(x\right)=\frac{x}{2}.$  4 este imaginea lui

• 2

• 4

• 8

 $f:\left\{-1,0,1,2\right\}\rightarrow B\ ,\ f\left(x\right)=2x^2-1$  Cel mai mic cardinal al lui B este

• 4

• 2

• 3

 $f:\left\{-1,0,1,2\right\}\rightarrow R.\ f\left(x\right)=2x-1$  Rezultatul calculului  $f\left(-1\right)-f\left(0\right)$  este

• -4

• 0

• -2

• 2