Math O level

• The man who was death

  11 Nov 05, 12:08

  Originally posted by redstone:

  Ya me too... nearly got heart attack...
  That question very dizzying....

  that qns i can do but i cannot do the first qns the one with two circles then the tangents
  
  and hor the qns 9 on the cone, the last part the cylinder one they say make large no/ of toys but i take the vol of the cone/vol of the cylinder only 2 leh.
  How to do har?? this qn like pri sch also can do one leh
• The man who was death

  11 Nov 05, 12:09

  did u all do graph or vectors?? i did graph but i think shld do vectors cos do graph until halfway no time
• DeathEdge

  11 Nov 05, 12:10

  i thought that one just take the cyclinder volume divide by toy volume? but must take note the cylinder volume is in m^3 while toy volume is in cm^3. Whats you guys answer?
• redstone

  11 Nov 05, 12:10

  Originally posted by The man who was death:

  that qns i can do but i cannot do the first qns the one with two circles then the tangents
  
  and hor the qns 9 on the cone, the last part the cylinder one they say make large no/ of toys but i take the vol of the cone/vol of the cylinder only 2 leh.
  How to do har?? this qn like pri sch also can do one leh

  The cylinder is in m, but the cone is in cm.....
• DeathEdge

  11 Nov 05, 12:11

  Originally posted by The man who was death:

  did u all do graph or vectors?? i did graph but i think shld do vectors cos do graph until halfway no time

  hmm, i finished paper 1 hr before hand.. did vector cause lazy to draw graph =/
• The man who was death

  11 Nov 05, 12:16

  Originally posted by DeathEdge:

  i thought that one just take the cyclinder volume divide by toy volume? but must take note the cylinder volume is in m^3 while toy volume is in cm^3. Whats you guys answer?

  i got change the cylinder vol to cm and then divide but get only 2 leh
  
  change to cm just x100 rite?? must be wrong lah shouldn't be 100
• The man who was death

  11 Nov 05, 12:17

  the first qn how to do leh?? i only know the reason for why one angle is 90
• rainee

  11 Nov 05, 12:17

  Originally posted by The man who was death:

  i got change the cylinder vol to cm and then divide but get only 2 leh
  
  change to cm just x100 rite?? must be wrong lah shouldn't be 100

  x100 three times, cos it is volume...
• DeathEdge

  11 Nov 05, 12:18

  Originally posted by The man who was death:

  the first qn how to do leh?? i only know the reason for why one angle is 90

  the others is basically trigo and similar triangle.
• The man who was death

  11 Nov 05, 12:20

  Originally posted by rainee:

  x100 three times, cos it is volume...

  pri sch maths i also forget
• The man who was death

  11 Nov 05, 12:21

  Originally posted by DeathEdge:

  the others is basically trigo and similar triangle.

  didn't think of that
• redstone

  11 Nov 05, 12:23

  Originally posted by rainee:

  x100 three times, cos it is volume...

  Means x300?
  
  I just take cylinder vol x100 cos is in metre......
  
  Then divide by cone....
• rainee

  11 Nov 05, 12:24

  Originally posted by redstone:

  Means x300?
  
  I just take cylinder vol x100 cos is in metre......
  
  Then divide by cone....

  x100 x100 x100=1000000
• redstone

  11 Nov 05, 12:24

  Originally posted by rainee:

  x100 x100 x100=1000000

  Sure?
• Ah Cek

  11 Nov 05, 12:25

  1m = 100cm
  
  so,
  
  (1m)^3 = (100cm)^3
  
  which gives
  
  1m^3 = 1000000cm^3
  
  this logic won't goes wrong
• rainee

  11 Nov 05, 12:25

  Originally posted by redstone:

  Sure?

  u r converting m^3 to (cm)^3?
• rainee

  11 Nov 05, 12:26

  Originally posted by Ah Cek:

  1m = 100cm
  
  so,
  
  (1m)^3 = (100cm)^3
  
  which gives
  
  1m^3 = 1000000cm^3
  
  this logic won't goes wrong

  yea...
• redstone

  11 Nov 05, 12:28

  Originally posted by rainee:

  u r converting m^3 to (cm)^3?

  So what's the answer?
  How many cones can be made?
• The man who was death

  11 Nov 05, 12:28

  Si lah!! paper 1 25 marks gone now p2 do not so well tmd!! should've done the vectors, the graph so hard to draw curve three times!!! nabei!!!
• rainee

  11 Nov 05, 12:29

  Originally posted by redstone:

  So what's the answer?
  How many cones can be made?

  I need to know the exact question to be able to give an exact answer...
  
  but I think just convert volume of cylinder to cm^3 first, then divide with the cone volume given?
• The man who was death

  11 Nov 05, 12:32

  Originally posted by redstone:

  So what's the answer?
  How many cones can be made?

  1000000/10??
  
  u know the surface area i also do wrong i find the triangle area then x2 and then + the hemisphere, shld just use the cone area then - the hemisphere area
• Ah Cek

  11 Nov 05, 12:34

  draw curve can cheat one mah. work back the answer using quadratic eqns & calculations and mark out the points on the x & y axis... then try to 'land' your curve on them... sure full marks!
• redstone

  11 Nov 05, 12:55

  Anyone knows the cylinder and cone answer?
• approximately89

  11 Nov 05, 13:28

  answer for the numbers of toys to be made
  
  vol.of cone+hemisphere(toy)= (1/3 x pi x 5^2 x 12) + (2/3 x pi x 5^3)
  
  =575.9 cm^3(round up to 576cm^3)
  
  vol. of metal cylinder= pi x (150)^2 x 200
  = 14137166.9cm^3 (round up to 14137167cm^3)
  
  therefore : numbers of toys made = 14137167cm^3 divide 576cm^3
  = 24543.69 (round up to 24544 toys)
  
  
• DeathEdge

  11 Nov 05, 13:35

  Originally posted by approximately89:

  answer for the numbers of toys to be made
  
  vol.of cone+hemisphere(toy)= (1/3 x pi x 5^2 x 12) + (2/3 x pi x 5^3)
  
  =575.9 cm^3(round up to 576cm^3)
  
  vol. of metal cylinder= pi x (150)^2 x 200
  = 14137166.9cm^3 (round up to 14137167cm^3)
  
  therefore : numbers of toys made = 14137167cm^3 divide 576cm^3
  = 24543.69 (round up to 24544 toys)
  
  

  i thought is 24545? i use uncorrected value leh..