126 reputation
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location Dublin, Ireland
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visits member for 1 year, 10 months
seen Aug 13 at 14:34

Computer Science Student


Jul
2
awarded  Curious
Apr
5
awarded  Popular Question
Jan
24
awarded  Popular Question
May
6
revised Is $R_K$ first countable?
Edited title.
May
6
suggested suggested edit on Is $R_K$ first countable?
Apr
30
accepted Proof by Induction solution not understood
Apr
30
comment Proof by Induction solution not understood
Thanks. What about this part? $(3m + 1)(3m + 2)(3m + 3)≤(3m + 3)^3 = 27(m + 1)^3$
Apr
30
awarded  Citizen Patrol
Apr
30
asked Proof by Induction solution not understood
Apr
26
awarded  Organizer
Apr
26
revised Orthogonality & Adjoint Operator
Added homework tag
Apr
26
suggested suggested edit on Orthogonality & Adjoint Operator
Apr
22
comment Injection / Surjection
I totally get that now. Thanks!
Apr
22
comment Injection / Surjection
@vadim123 Well yes, but I don't know if it's injective or not at the start. The goal is to find out. So 4 & -4 are both elements of A, right? And they can't both be mapped to the same element in B, making the function NOT injective, right?
Apr
22
comment Injection / Surjection
@TheChaz2.0 This is how I like to define it. Injective means that every member of "A" has its own unique matching member in "B".link
Apr
22
comment Injection / Surjection
Sorry, I'm just trying to get my head around this. So if $x = 1$, it's compliment is $-1$, right? But for injection, $x$ must equal $x'$. Can you give me an example where $x$ actually equals to $x'$. I can't think of any.
Apr
22
comment Injection / Surjection
I only understand how this works when I imagine two sets, A & B. So 4 is A and -4 is B. Injection means that for every element in A, there's a uniqe one in B, right? But because there's limit, which in 3, right? -13 is then invalid. Is any of what I said right?
Apr
22
comment Injection / Surjection
Is $4$ just a random number? Why 4?
Apr
22
asked Injection / Surjection
Apr
22
revised Injective & Surjective
added 22 characters in body