1. ## infimum and minimum

For each subset of R, give its infimum and and the minimum of each set, if they exist. Otherwise write "none"
a) {1,3}
b) {pi, 3}
c) [0,4]
d) (0,4)
e) {1/n: n is an element of N}
f) {1 - 1/n: n is an element of N}
g) {n/(n+1): n is an element of N}
h) {(-1)^n(1+1/n): n is an element of N}
i) {n + (-1)^n/n: n is an element of n}
j) (-infinity, 4)
m) {r is an element of Q: r<5}
n) {r is an element of Q: r^2<=5}

thanks for everyones help!

2. Originally Posted by luckyc1423
For each subset of R, give its infimum and and the minimum of each set, if they exist. Otherwise write "none"
a) {1,3}
b) {pi, 3}
c) [0,4]
d) (0,4)
e) {1/n: n is an element of N}
f) {1 - 1/n: n is an element of N}
g) {n/(n+1): n is an element of N}
h) {(-1)^n(1+1/n): n is an element of N}
i) {n + (-1)^n/n: n is an element of n}
j) (-infinity, 4)
m) {r is an element of Q: r<5}
n) {r is an element of Q: r^2<=5}

thanks for everyones help!
a) infimum=minimum=1
b) infimum=minimum=3
c) infimum=minimum=0
d) infimum=0 minimum= none
e) infimum=0 minimum= none
f) infimum=minimum=0
g) infimum=minimum=1/2
h) infimum=minimum= -2
i) infimum=minimum=0
j) infimum=minimum= none
m) infimum=minimum= none
n) infimum= -sqrt(5) minimum= none

3. Ur really good at this stuff, how did you get so good just by practice? I practice all the time on this material and it never clicks...it seems like every problem is different and once I understand one problem im confused on the next.

4. Originally Posted by luckyc1423
Ur really good at this stuff, how did you get so good just by practice? I practice all the time on this material and it never clicks...it seems like every problem is different and once I understand one problem im confused on the next.
well, i dont really practice stuff like this a lot. i just go based on the definitions. make sure you understand what the definitions mean and how to apply them