Recent content by chemistry1

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    Determine if a Molecule is Polar - Steps & Tips

    Well, I know how to add vectors but only if they're 2d...
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    Determine if a Molecule is Polar - Steps & Tips

    Hi, I know what are the steps to determine if a molecule is polar or not, but I'm having one small problem. When I have determined the geometrical shape of my molecule and drew the vectors of the polar bonds that goes from the least electronegative atom to the most electronegative atom, how...
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    Undergrad Notation Question: Understanding "y --> 2^(-) implies y < -2

    Yes, I also noticed it. Ok, thank you!
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    Undergrad Notation Question: Understanding "y --> 2^(-) implies y < -2

    But shouldn't we say : y --> -2^(-) and not y --> 2^(-) ?
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    Undergrad Notation Question: Understanding "y --> 2^(-) implies y < -2

    Hi, I have a question about : http://imgur.com/RU7PvtJ I actually understand what I need to do. I need to see if both one sided limits are the same to establish that the limit exists. The only thing which I just find weird is the "since y --> 2^(-) implies y<-2" Can somebody explain me...
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    Undergrad Understanding Limits: A Question about Inequalities

    Nah, its okay, no need for that anymore.
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    Undergrad Understanding Limits: A Question about Inequalities

    I was wondering, when we consider several functions at once in the same graph, is it ok if this whole is not a function itself ? Do we care about whether this whole is function or not ?
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    Undergrad Understanding Limits: A Question about Inequalities

    Hi, I'm having trouble understanding the following fact about limits : If f(x)<=g(x) for all x on (a,b) (except possibly at c) and a<c<b then, lim f(x) <= lim g(x) x -> c x->c Here's how I interpret the definition : We have two functions f(x) and g(x), and the inequality f(x)<=g(x)...
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    Undergrad Why do we need postulate 4 in Euclid's element (P14)?

    I don't think I understand your explanation... Didn't Euclid "prove" with proposition 13 that the sum of two angles were equal to two right angles ? And that we begin the demonstration assuming that the sum of the angle CBA and ABD were equal to two right angles ? What role does postulate 4 play...
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    Undergrad Why do we need postulate 4 in Euclid's element (P14)?

    http://aleph0.clarku.edu/~djoyce/java/elements/bookI/propI14.html Hi, I was reading proposition 14 of Euclid's elements and there is only one thing which I find weird : why do we need postulate 4 to conclude that " the sum of the angles CBA and ABE equals the sum of the angles CBA and ABD."...
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    High School A null set is a subset of every set

    Well, I do understand your first part. Now, for the second part, are you saying that because the empty set has no elements, it can't satisfy(be a subset) of B?
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    High School A null set is a subset of every set

    Hi, I was wondering, how can a null set be a subset of other sets? Could anyone explain the idea in non technical terms, I'm just a beginner. :) Thank you!
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    Create Your Sundae - 45 Combination Options for Two Scoops

    Ok, Thank you again. I didn't know the standard way...^^
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    Create Your Sundae - 45 Combination Options for Two Scoops

    Well, we need two different sorts, so we have a total combination of 9 for 10 different flavour. For example, if we consider each flavour a number, then : (1,2) (1,3) ... til (1,10) Now, if we want to see for the second flavour, we already did the combination (1,2), so we must substract 1...
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    Create Your Sundae - 45 Combination Options for Two Scoops

    Hi, An ice cream shop sells ten different flavors of ice cream. You order a two- scoop sundae. In how many ways can you choose the flavors for the sundae if the two scoops in the sundae are different flavors? That's what I did : 9+(9-1)+(9-2)+...+(9-9)=45 Would this be any good ...