Recent content by mathcnc

ok so u are saying denumerable and countable are the same thing?

ok i will look However, nothing more is said about a thats the whole problem

Homework Statement Prove by induction that if set S = {x1,x2...,xn} is a set of n elements non of which are in a set A, then AuS is denumerable Homework Equations im not sure what to put here The Attempt at a Solution what does this mean denumerable? and how do i start this I...

so liek i would say that (1,2) is a subset and it have infinite cardinality and so (1,5) does? im sorry I am just having major issues with going about how to prove this

i don't know I am so confused!

Homework Statement Prove the intervals of real numbers (1,3) and (5,15) have the same cardinality by finding an appropriate bijective function of f:(1,3) ->(5,15) and verifying it is 1-1 and onto Homework Equations I know there are multiple ways to prove one to one and onto I am not sure...