Question

Se dau multimile :
A= {x∈Ν/$x^{3}$<100}
B= {y∈N*/5y$\leq$ 34 }
C= {z∈N/$z^{2}$ - 3 $\leq$ 30 }
Calculati :
a) A U B U C
b) A ∧ C (adica U intors)
c) A \ B
d) B \ C

Answer 1

A = {0,1,2,3,4}
5y ≤ 34 

=> y∈{1,2,3,4,5,6}
=> B={1,2,3,4,5,6}
z²-3≤30 => z²≤33 => z ∈ {0,1,2,3,4,5} => C = {0,1,2,3,4,5}
Atunci:
a) A U B U C = {0,1,2,3,4,5,6}
b) A ∧ C = {0,1,2,3,4,5}
c) A \ B = {0}
d) B \ C = {6}