Cmdr. Cracken Posted January 30, 2001 Posted January 30, 2001 Keyan, or any other math geniuses, can you help me under stand functions and function notation? (Not in C++, ADV. ALGEBRA)
Admiral Odin Posted January 30, 2001 Posted January 30, 2001 a function is anything that passes the the y axis only once. for instance f(x)=2x(sq)+x if you give a number say 4 you get. 2(4)(sq)+4=36 ------------------ "Dulce bellum inexpertis." (Sweet is war to those who have never experinced it.) Roman Proverb
Rogue Nine Posted January 30, 2001 Posted January 30, 2001 You could show them to us, dunno if I personally will be of any help...
Keyan Farlander Posted January 30, 2001 Posted January 30, 2001 Originally posted by Admiral: a function is anything that passes the the y axis only once. NO!!! That is not true at all! It is true that if it does pass the y axis more than once, it is not a function, but it needs much more to actually be a function. A function is a mapping from one set of values to another. The key is that no element from the domain ("mappers") can map to more than one element of the range ("mappees"). Now, two or more elements of the domain can map to the same member of the range - that makes no difference. So if you think about it in terms of the graph, no two points can be on top of each other. The graph cannot cross ANY vertical line more than once.
Rogue Nine Posted January 30, 2001 Posted January 30, 2001 The great and amazing Keyan has spoken! Be stupefied! ------------------ Love people. Use things. Not vice versa. XWA's Resident Finance Manager
Keyan Farlander Posted January 31, 2001 Posted January 31, 2001 You know it, baby. I may be a loser in almost everything else, but I know my math.
Psycho Tycho Posted January 31, 2001 Posted January 31, 2001 Yeccch, math. Forget about math. Yeccch, school.
Guest Zoom Rabbit Posted January 31, 2001 Posted January 31, 2001 I function as a biological perambulation unit!
Admiral Odin Posted January 31, 2001 Posted January 31, 2001 Your right Keyan. I haven't used functions for over a year so...must have forgotten some. we need to chat some math some time. Cracken if you can post some problems I could help some more. ------------------ "Dulce bellum inexpertis." (Sweet is war to those who have never experinced it.) Roman Proverb
Gold leader Posted January 31, 2001 Posted January 31, 2001 Originally posted by Admiral: a function is anything that passes the the y axis only once. Admiral, you should have known better. f(x) = 1/x is a function, but it never actually passes the y-axis.
Keyan Farlander Posted January 31, 2001 Posted January 31, 2001 Why? It's pretty obvious what it will look like.
Rogue Nine Posted January 31, 2001 Posted January 31, 2001 Yeah, but no one else is a frickin' genius like you, Keyan.
Keyan Farlander Posted January 31, 2001 Posted January 31, 2001 Um, thanks But I meant what is your point about graphing that? I'm not sure what you're getting at. Something about the discontinuity?
Rogue Nine Posted January 31, 2001 Posted January 31, 2001 Tis a line, isn't it? ------------------ Love people. Use things. Not vice versa. XWA's Resident Finance Manager
Admiral Odin Posted January 31, 2001 Posted January 31, 2001 I am bad with graphs, I like using my calculator for those. ------------------ "Dulce bellum inexpertis." (Sweet is war to those who have never experinced it.) Roman Proverb
Keyan Farlander Posted February 1, 2001 Posted February 1, 2001 A line? That function is not a line. Speak up, R9, what are you getting at?
Cmdr. Cracken Posted February 1, 2001 Author Posted February 1, 2001 so, how would i evaluate this.....? g(x)=x^2-3x when g(4) would I just substitue x for for, since g(4)?
Cmdr. Cracken Posted February 1, 2001 Author Posted February 1, 2001 I think i know what R9 is getting at. a function is any line on a graph that passes the vert. Line test. Vertical line test=You place a vertical line anywhere on the line. if the vertical line crosses the line more than ONCE, then the line is not a function. R9's sentence (x-4)^2/x-2 will probably fail this test.
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