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two quick maths problems

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  • WoAiMeiMei
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    180 posts since Jul '07
    • 15 Apr `08, 6:06PM

      -all questions completed-

      -all questions completed-

      Edited by WoAiMeiMei 16 Apr `08, 8:34PM
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    eagle
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    17,973 posts since Aug '01
  • WoAiMeiMei
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    180 posts since Jul '07
    • 15 Apr `08, 6:13PM

      wth does the second question mean? >_<

       

       

       

      hmm due thurs at 6

      Edited by WoAiMeiMei 15 Apr `08, 6:14PM
  • weewee
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    498 posts since Aug '03
    • 15 Apr `08, 6:16PM
      Originally posted by WoAiMeiMei:

      will work on this tonight, just need comparisons because scared i'll stuff up hey : O


      Q1) when x = 1.6

      6y^2 +6y=8(1.6) +7=19.8

      6y^2 +6y-19.8=0

      y=[-6+-sqrt(36-4*6*-19.8)]/12

      y=1.3841 or y=negative number (rejected)

      At this point, differentiate implicitly with respect to x.

      (12y + 6 )(dy/dx) = 8

      dy/dx = 0.3538

       

      Edited by weewee 16 Apr `08, 12:34AM
  • weewee
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    498 posts since Aug '03
    • 15 Apr `08, 6:30PM

      For Q2) I am not sure but w-axis is a 3dimensional axis but it is not like the z-axis. Since it is protrayed at an angle, it means w-axis is not completely independent from the x and y-axis. The angle 235 degree means it is an 360-235=125degree looking from the other direction. It means the w-axis make a 125 degree wrt to the x and y axis.

  • WoAiMeiMei
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    180 posts since Jul '07
    • 15 Apr `08, 6:36PM

      haha i will check that out later after i complete a few sets. thanks for the help! be back soon!

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    eagle
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    17,973 posts since Aug '01
  • WoAiMeiMei
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    180 posts since Jul '07
  • WoAiMeiMei
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    180 posts since Jul '07
    • 15 Apr `08, 8:01PM

      crap... what are gradient units for q1? it's not m

       

      theoratically it shuld cancel out -__-

      Edited by WoAiMeiMei 15 Apr `08, 8:03PM
  • FirePig
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    1,183 posts since Mar '08
  • WoAiMeiMei
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    180 posts since Jul '07
    • 15 Apr `08, 8:14PM

      is it me or did weewee forget the 6 infront of the y^2?

       

      @firepig: the program is hell effed up. u need to use "m/m" as ur units. wth

      Edited by WoAiMeiMei 15 Apr `08, 8:15PM
  • 16/f/lonely
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    3,812 posts since Apr '08
  • WoAiMeiMei
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    180 posts since Jul '07
  • WoAiMeiMei
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    180 posts since Jul '07
    • 16 Apr `08, 7:52PM

      i think we need to find some angles for question 2 and times pq by cos *angle* to get the component

  • WoAiMeiMei
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    180 posts since Jul '07
    • 16 Apr `08, 8:33PM

      yes! i did question 2 : D

       

      the answer is 25.644

       

      from 31.016 cos 34.227

      the 31.016 is the length of PQ, the angle 34.227 i worked out from similar angles and from the inverse tan of the PQ thingo... >_<

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