Saturday, October 16, 2010

About Relationships... a conversation...

{in the middle of a conversation...}
  • ME: have a good breakfast... that helps :) er... not a too heavy one... else zzzzz monster will visit u
  • ACE: my breakfast is coming later....
  • ME: Have a cup of beverage that wakes u up :) into my 2nd cup of coffee this morning :)
  • ACE: O_O i tot it's not too good to have so much coffee O_O
  • ME: hehehe.... hm... proportional to age (I guess) hahaha.... it follows a linear graph hahahahhaahha
  • ACE: hahaha.. linear graph O_O eeek i wonder if i still rmb the way to do it ==
  • ME: oh... understanding what it means (esp the equation) helps :)
  • ACE: hmm
  • ME: hm.... y = mx + c. So, imagine the equation that represents number of cups of coffee we drink per day is.... y = 0.005 x where x is the age. oops! one could only drink a cup of coffee when reach the age of .... 200!!!! hahahaha..... oops! hope that's not confusing to you :)
  • ACE: O_O ooh i think i understand
  • Loh: hahah... Hm... maybe a more realistic equation would be y = 0.05 x (where y represents the number of cups of coffee) and x is the age
  • ACE: we must make y = 1. Is it O_O
  • ME: ah... then at what age, theoretically speaking when one is eligible for 1 cup of coffee
  • ACE: according to the equation or...
  • ME: .... (waiting for the "age') hehehe.....
  • ACE: 20
  • ME: :)
  • ACE: ooh i see...
  • ME: hahah... pretty easy hor
  • ACE: hmm then while drawing the graph i know c is the y-intercept and m is the gradient.. but what is y and x?
  • ME: x and y are any items that we want to create a relationship... ok... it sounds a bit vague. Use the earlier example, u notice we want to describe a relationship between age and no. of cups of coffee?
  • ACE: yup
  • Loh: so, we let y represents no. of cups and x represents age. So, to describe how x and y are related there are some 'facts' (that could be discovered through research). So, people realised that when one gets older, the number of cups of coffee also increases so it becomes y (no. of cups) = a description times x (age)
  • ACE: hmm..
  • Loh: the description is 'how fast'
  • ACE: i see.
  • ME: so, maybe research shows that it's 0.05 times the age then we describe it as y = 0.05 x
  • ACE: so the relationship is the when y increases x also increases.
  • ME: yes....
  • GRACE: ooh
  • Loh: remember the graph of y = 0.05x is moving upwards (from left to right of the graph paper) so, it's a positive relationship hm... we can also describe something else like...
  • ACE: oh
  • ME: amount of hair one has... as one ages.... ok... this case, we'll have something like from the age of 40 to 100 so guess how the graph would look like if y represents the amount of hair and x represents the age (age starting from 40) hahahah.....
  • ACE: hm... what is m ?
  • ME: :) of course, we are not talking about exceptional cases like those who shave their head.... hm... m is to describe how fast the hair drops... hahahhha.... or the rate that hair grows?
  • ACE: ...... so i can replace it with any number?
  • ME: 'cos as one gets older... the rate of hair growth also significantly reduced :) ah... u can place it with any number... then test out to see if it's logical
  • ACE: hmm... y=20x ?
  • ME: but before that, we'll have to ask ourselves... is the number going to increase or decrease as age increases
  • ACE: ok
  • ME: hm... so, if you look at y = 20x. it means as one grows older, the amount of hair would increase? (this is true when we look at... starting from baby to around the age of 40?)
  • ACE: ok. So if we change 20 to -20?
  • ME: good suggestion :) - implies getting lesser and lesser... however we can't have negative number of hair on the head. Hahahha..... the most we could go to is zero hair
  • ACE: so decrease the number? oh
  • ME: :) so... hm... here, the y-intercept might come in useful
  • ACE: O_O then now what O_O
  • ME: use what you have... maybe we can try something like y = -20x + 400. we add the y-intercept to make the relationship more realistic so, if one is 10 years old, does he have any hair?
  • ACE: hmm yeah 200
  • ME: :)
  • ACE: oohhh
  • ME: so, by the age of 40.... haha... nothing's left.
  • ACE: yup
  • ME: so it could be a special scenario whereby someone was struck with some sickness
    and the equation could be used to describe the hair loss... which is, y = -20x + 400 well... this is a very simplistic way of describing relationships
  • ACE: i see thanks xD
  • ME: in real world... more complex... that's why we move into quadratic equations, etc....
    :) Enjoy :)
  • ACE: i see tyty! :D

Sent at 7:48 AM on Saturday

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