Yahoo Answers: Answers and Comments for Prove f(M,n)=2^(m1) (2n1) is an injection and surjection? [Mathematics]
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enSG
Wed, 21 Apr 2010 14:12:10 +0000
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Yahoo Answers: Answers and Comments for Prove f(M,n)=2^(m1) (2n1) is an injection and surjection? [Mathematics]
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https://sg.answers.yahoo.com/question/index?qid=20100421141210AABj6A3
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From Curtischoy: This looks messy so I'm not actually going...
https://sg.answers.yahoo.com/question/index?qid=20100421141210AABj6A3
https://sg.answers.yahoo.com/question/index?qid=20100421141210AABj6A3
Wed, 21 Apr 2010 23:31:11 +0000
This looks messy so I'm not actually going to do it. i'll just give you a little help.
Im going to assume f:R to R (f is a function from the reals to the reals)
To prove that a function is injective you need to prove: for all x,y in R if f(x)=f(y) then x=y
So start with: 2^(m1)(2n1)=2^(x1)(2y1) and try to reach the conclusion m=x and n=y.
To prove that a function is surjective you need to prove: for all a in R, there exists a b in R such that f(a)=b
So show that 2^(m1)(2n1) is in R.