core help...please :) URGENT

[spikey]

geog/trig exam 1 2010 q. 8 = lulwut? so screwed!

[Keo]

Keep asking questions guys! it's the ones you dont know that wil stump you on the exam! =)

hang on. im working through that bloody question still... gah. so what do each of the equations mean exactly? like what exactly are we finding the height of for each?

its saying between 0≤length≤4.5
1/2*L+3 => it says the roof starts at a height of 3 metres and goes up by a 1/2

between 4.5≤length≤10
-1/6*L+5 => roof begins here at 5 metres and goes down by 1/6 but it stops at a length of 10 metres

[harlequinphoenix]

Keep asking questions guys! it's the ones you dont know that wil stump you on the exam! =)

hang on. im working through that bloody question still... gah. so what do each of the equations mean exactly? like what exactly are we finding the height of for each?

its saying between 0≤length≤4.5
1/2*L+3 => it says the roof starts at a height of 3 metres and goes up by a 1/2

between 4.5≤length≤10
-1/6*L+5 => roof begins here at 5 metres and goes down by 1/6 but it stops at a length of 10 metres

oh yeah, thats where the constraints come into it. thanks Now its kind of the expanding of (b/2+30-9-b/6+5) = 1 thats confusing me.... :S do you have any tips for expanding? like to get to 4b/6=3

[DannyN]

Keep asking questions guys! it's the ones you dont know that wil stump you on the exam! =)

hang on. im working through that bloody question still... gah. so what do each of the equations mean exactly? like what exactly are we finding the height of for each?

its saying between 0≤length≤4.5
1/2*L+3 => it says the roof starts at a height of 3 metres and goes up by a 1/2

between 4.5≤length≤10
-1/6*L+5 => roof begins here at 5 metres and goes down by 1/6 but it stops at a length of 10 metres

oh yeah, thats where the constraints come into it. thanks Now its kind of the expanding of (b/2+30-9-b/6+5) = 1 thats confusing me.... :S do you have any tips for expanding? like to get to 4b/6=3

expand everything first including brackets     
 (b/2+3)-(-b/6+5)=1 ----> b/2+3+b/6-5=1

b/2+b/6-2=1   --->bring -2 to the other side, when taking a number and moving it to the other side the sign changes, in this case - turns into +
b/2+b/6=1+2
b/2+b/6=3
do simple factions to add fractions the denominator must be the same, getting lazy now =P
3b/6+b/6=3
4b/6=3
 

[harlequinphoenix]

Keep asking questions guys! it's the ones you dont know that wil stump you on the exam! =)

hang on. im working through that bloody question still... gah. so what do each of the equations mean exactly? like what exactly are we finding the height of for each?

its saying between 0≤length≤4.5
1/2*L+3 => it says the roof starts at a height of 3 metres and goes up by a 1/2

between 4.5≤length≤10
-1/6*L+5 => roof begins here at 5 metres and goes down by 1/6 but it stops at a length of 10 metres

oh yeah, thats where the constraints come into it. thanks Now its kind of the expanding of (b/2+30-9-b/6+5) = 1 thats confusing me.... :S do you have any tips for expanding? like to get to 4b/6=3

expand everything first including brackets     
 (b/2+3)-(-b/6+5)=1 ----> b/2+3+b/6-5=1

b/2+b/6-2=1   --->bring -2 to the other side, when taking a number and moving it to the other side the sign changes, in this case - turns into +
b/2+b/6=1+2
b/2+b/6=3
do simple factions to add fractions the denominator must be the same, getting lazy now =P
3b/6+b/6=3
4b/6=3
 

omg. i totally forgot that you could add fractions >.< thank you soooo much. one thing I didn't get though is why the b/6+5 turned into -5 upon expansion? is it because the minus sign between brackets is basically a negative 1? and so the signs change within the brackets?..

[harlequinphoenix]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

[DannyN]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

[harlequinphoenix]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

omg i love you. this bloody expanding brackets shit always gets me, i forget to put it in brackets and just do the equation as a whole which was NOT working. thank you you've been so helpful! And keo too of course!

[DannyN]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

omg i love you. this bloody expanding brackets shit always gets me, i forget to put it in brackets and just do the equation as a whole which was NOT working. thank you you've been so helpful! And keo too of course!

no worries, keo is stressing atm i get to kick him in the nuts as hard as i can if he doesnt get a 50. So ima keep bugging him so that he gets a 49 LOL

[harlequinphoenix]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

omg i love you. this bloody expanding brackets shit always gets me, i forget to put it in brackets and just do the equation as a whole which was NOT working. thank you you've been so helpful! And keo too of course!

no worries, keo is stressing atm i get to kick him in the nuts as hard as i can if he doesnt get a 50. So ima keep bugging him so that he gets a 49 LOL

oh my gosh that's mean haha!! good luck to him! And to you if you are doing it. i better get to bed soon , night and thanks heaps!

[harlequinphoenix]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

omg i love you. this bloody expanding brackets shit always gets me, i forget to put it in brackets and just do the equation as a whole which was NOT working. thank you you've been so helpful! And keo too of course!

no worries, keo is stressing atm i get to kick him in the nuts as hard as i can if he doesnt get a 50. So ima keep bugging him so that he gets a 49 LOL

oh my gosh that's mean haha!! good luck to him! And to you if you are doing it. i better get to bed soon , night and thanks heaps!

[DannyN]

incidentally, i just came across a simultaneous equation I meant to check how to do about 6 months ago ^_^ it's a sub one so i wasnt sure how to plug it into the calc. it is x = 3.5 - 3y and 3y - 2x = 11 if SEs are anybody's forte out there!

im bored so might as well, there are two methods 1. elimination 2. substitution

if x = 3.5 - 3y and 3y - 2x = 11
just plug it in haha
put x=3.5 - 3y   into 3y - 2x = 11
3y - 2(3.5-3y) = 11 ----->expand brackets    3y-7+6y=11
9y=11+7
9y=18
therefore y=2
to find x sub y=2 into x=3.5 - 3y
x=3.5-3(2)
x=3.5-6
therefore x=-2.5

omg i love you. this bloody expanding brackets shit always gets me, i forget to put it in brackets and just do the equation as a whole which was NOT working. thank you you've been so helpful! And keo too of course!

no worries, keo is stressing atm i get to kick him in the nuts as hard as i can if he doesnt get a 50. So ima keep bugging him so that he gets a 49 LOL

oh my gosh that's mean haha!! good luck to him! And to you if you are doing it. i better get to bed soon , night and thanks heaps!

no worries, haha i'll sleep soon! and good luck to you too! yeah im doing further this year since i screwed up methods >.>

[ech_93]

Ah! I can't work out how to do question 9, exam 1, VCAA 2007..... Help please

[DannyN]

Ah! I can't work out how to do question 9, exam 1, VCAA 2007..... Help please

it says to linearise the scatterplot you must, apply a log(y) transformation, you must use your calculator for this, which calc do you have?

[ech_93]

Dw, worked it out. I was doing log e instead of log 10..... Thanks anyway