Question

Fie A={x∈N*/x≤4}. Determinati multimile:
A={x∈N*/≤4}
B={y∈N/y=2x+1,x∈A};
C={z∈N/z=2^x,x∈A};
D={t∈N/t=x^3,x∈A};
E={u∈N/u=3x-1,x∈A}
F={v∈N/t=x^2-1,x∈A}
G={w∈N/w=2x^2+x,x∈A}

Answer 1

A={1, 2, 3, 4}
y=2x+1
y=2×1+1=2+1=3
y=2×2+1=4+1=5
y=2×3+1=6+1=7
y=2×4+1=8+1=9
B={3, 5, 7, 9}
z=2^x
z=2^1=2
z=2^2=4
z=2^3=8
z=2^4=16
C={2, 4, 8, 16}
t=x^3
t=1^3=1
t=2^3=8
t=3^3=27
t=4^3=64
D={1, 8, 27, 64}
u=3x-1
u=3×1-1=3-1=2
u=3×2-1=6-1=5
u=3×3-1=9-1=8
u=3×4-1=12-1=11
E={2, 5, 8, 11}
t=x^2-1
t=1^2-1=1-1=0
t=2^2-1=4-1=3
t=3^2-1=9-1=8
t=4^2-1=16-1=15
F={0, 3, 8, 15}
w=2x^2+x
w=2×1^2+1=2×1+1=2+1=3
w=2×2^2+2=2×4+2=8+2=10
w=2×3^2+3=2×9+3=18+3=21
w=2×4^2+4=2×16+4=32+4=36
G={3, 10, 21, 36}