Question

Explicitati modulul:
a) {x∈R,|x|≤7}
b) {x∈R,|x|≤0}
c) {x∈R,|x|>0}
d) {x∈R,|x|≥√5}

Answer 1

a) {x∈R,|x|≤7}=[-7,7]
b) {x∈R,|x|≤0}={0}
c) {x∈R,|x|>0}=R-{0}
d) {x∈R,|x|≥√5}=(-∞,-√5]U[√5,+∞)