Question

Determinați Imf in fiecare dintre cazurile următoare:
a) f:{-2;-1;0;1;2} ->R,f(x)=2x+3
b) f:{-3;-2;-1;0;1}->R,f(x)=x la puterea 2

Answer 1

a) f(-2)=2×-2+3= -4+3= -1
f(-1)=2×-1+3= -2+3=1
f(0)=2×0+3=3
f(1)=2×1+3=2+3=5
f(2)=2×2+3=4+3=7
Imf={-1,1,3,5,7}

b) f(-3)=(-3)^2=9
f(-2)=(-2)^2=4
f(-1)=(-1)^2=1
f(0)=0
f(1)=1^2=1
Imf={0,1,4,9}