VCE Methods Question Thread!

[alchemy]

'Don't drink and drive.'

We don't drink in the first place -_-
EDIT: Actually some of the older members here might, so LOL

[BubbleWrapMan]

We don't drink in the first place -_-
EDIT: Actually some of the older members here might, so LOL

All of the mods remain sober at all times. It sets a good example for VCE students.

[Phy124]

I don't want to sound like an idiot, but if I'm making these mistakes, do i really have a chance at methods?  I'm freaking out, i've nearly completed chapter 1 of the methods 1-2 concept book, i've done every question thus far obviously made mistakes but learnt from them.  I'm just really worried if its going to get hard and i get left behind.

Don't worry mate, everyone makes mistakes and with practice they can be greatly reduced. From what I have observed you have been putting a lot of work into studying during the holidays and this will put you in good stead next year and hopefully prevent yourself from falling behind, keep up the good work

We don't drink in the first place -_-

...awks

All of the mods remain sober at all times. It sets a good example for VCE students.

Disregard my previous statement, can confirm sobriety.

[Only Cheating Yourself]

Don't worry mate, everyone makes mistakes and with practice they can be greatly reduced. From what I have observed you have been putting a lot of work into studying during the holidays and this will put you in good stead next year and hopefully prevent yourself from falling behind, keep up the good work
...awks
Disregard my previous statement, can confirm sobriety.

Thanks mate.  Also how do you + someone?  Theres a sign up top but i click then it goes from +1 to +2?

[brenden]

Thanks mate.  Also how do you + someone?  Theres a sign up top but i click then it goes from +1 to +2?

That's because someone else has already clicked the 'plus' sign, making it go from 0 to +1. When the next person does it, it goes to +2, and +3 and so on. The "+(number)" is a representation of how many people have clicked the 'plus' sign =]

[Only Cheating Yourself]

Find the equation of a line containing the intersection of the lines with equations y=-3x+4 and 5x-3y+40=0

d.)  is parallel with the line joining (-8,5) (0,4)

I use the the cordinates above to find M=4-5=-1 0+8=8
M=-x/8  This part is correct

But this is where I'm wrong and i need help…

So now what i did was i assumed (-8,5) is =x1 and y1 so i use the formula

y-5=-x/8(x+8)
8y-40=-x-8
x+8y-40=-8
x+8y-32=0
x+8y=32
y=4

now i put into mx+c to complete the question

y=x-/8x+4 

But my answer is incorrect the book says its y=-x/8+39/4

[Phy124]

Find the equation of a line containing the intersection of the lines with equations y=-3x+4 and 5x-3y+40=0

d.)  is parallel with the line joining (-8,5) (0,4)

I use the the cordinates above to find M=4-5=-1 0+8=8
M=-x/8  This part is correct

But this is where I'm wrong and i need help…

So now what i did was i assumed (-8,5) is =x1 and y1 so i use the formula

y-5=-x/8(x+8)
8y-40=-x-8
x+8y-40=-8
x+8y-32=0
x+8y=32
y=4

now i put into mx+c to complete the question

y=x-/8x+4 

But my answer is incorrect the book says its y=-x/8+39/4

y=-3x+4 and 5x-3y+40=0 intersect at (x,y) = (-2,10)

The line joining the two points (-8,5) (0,4) will have gradient -1/8

y-y1 = m(x-x1)

y - 10 = -1/8(x--2)

y - 10 = -x/8-1/4

y = -x/8 + 39/4

Where you went wrong is that you have shown working for a line that goes through the points (-8,5) and (0,4) but we are looking for a line that is parallel to the one you found i.e. same gradient but different points (specifically the point (-2,10))

[Only Cheating Yourself]

y=-3x+4 and 5x-3y+40=0 intersect at (x,y) = (-2,10)

The line joining the two points (-8,5) (0,4) will have gradient -1/8

y-y1 = m(x-x1)

y - 10 = -1/8(x--2)

y - 10 = -x/8-1/4

y = -x/8 + 39/4

Where you went wrong is that you have shown working for a line that goes through the points (-8,5) and (0,4) but we are looking for a line that is parallel to the one you found i.e. same gradient but different points (specifically the point (-2,10))

I actually tried this but i got 39/8 not 39/4.  isn't it 8y not 4y?

Also this is another problem i have with maths, i actually don't really know whats going on and what we are finding I've kinda just remember few things and going off that if that makes sense…

[Phy124]

I actually tried this but i got 39/8 not 39/4.  isn't it 8y not 4y?

Sorry, I'm not quite sure what you mean?

Also this is another problem i have with maths, i actually don't really know whats going on and what we are finding I've kinda just remember few things and going off that if that makes sense…

Alright so lets break down the question.

Find the equation of a line containing the intersection of the lines with equations y=-3x+4 and 5x-3y+40=0

So we have two lines y = -3x+4 and 5x-3y+40=0

Lets draw these out:

https://www.desmos.com/calculator/vd9tpqajas

We know that they intersect at (-2,10) (either found through simultaneous equations or graphical method)

We are looking for a line which contains the point of intersection of the two aforementioned lines. This point is (-2,10) as previously found so the line goes through the point (-2,10).

Next we are told: 

d.)  is parallel with the line joining (-8,5) (0,4)

So we have a line that goes through the point (-2,10) and it is parallel to a line that goes through the points (-8,5) and (0,4). Lets draw this second line in to help us.

https://www.desmos.com/calculator/kyds56ozdm

As the line we are trying to find is parallel to this line they must have the same gradient.

So we know that the lines has gradient -1/8 and goes through the point (-2,10)

Then we simply use the formula as in my previous post to find this line.

Lets draw the line we've found in:

https://www.desmos.com/calculator/qj8jgbechw

Looks right to me, next question.

Make sure you read the question carefully and multiple times to make sure you know what you're trying to find. Also once you do a lot of problems and build up some confidence you'll hopefully be able to visualise it all in your head and it'll be much easier.

[Apink]

I actually tried this but i got 39/8 not 39/4.  isn't it 8y not 4y?

Do you mean like this?









It'll simplify at the end.

[Only Cheating Yourself]

Sorry, I'm not quite sure what you mean?

Alright so lets break down the question.
So we have two lines y = -3x+4 and 5x-3y+40=0

Lets draw these out:

https://www.desmos.com/calculator/vd9tpqajas

We know that they intersect at (-2,10) (either found through simultaneous equations or graphical method)

We are looking for a line which contains the point of intersection of the two aforementioned lines. This point is (-2,10) as previously found so the line goes through the point (-2,10).

Next we are told: 
So we have a line that goes through the point (-2,10) and it is parallel to a line that goes through the points (-8,5) and (0,4). Lets draw this second line in to help us.

https://www.desmos.com/calculator/kyds56ozdm

As the line we are trying to find is parallel to this line they must have the same gradient.

So we know that the lines has gradient -1/8 and goes through the point (-2,10)

Then we simply use the formula as in my previous post to find this line.

Lets draw the line we've found in:

https://www.desmos.com/calculator/qj8jgbechw

Looks right to me, next question.

Make sure you read the question carefully and multiple times to make sure you know what you're trying to find. Also once you do a lot of problems and build up some confidence you'll hopefully be able to visualise it all in your head and it'll be much easier.

Hey thanks, i've done like a whole chapter worth of these questions but because I've done so many its like i've remembered what to rather knowing what I'm doing.  I actually don't really understand the question

So are we trying to find an equation that crosses/intersects with y=-3x+4 and 5x-3y+40=0?  If so i understand we need a gradient and x1 and y1 so we can use the formula am i right?  But i don't understand which gradient we find an which x1 and y 1 we find

[Only Cheating Yourself]

Do you mean like this?









It'll simplify at the end.

yes i did i just didn't simplify 78/8, can you read my above post. Please thanks

[Only Cheating Yourself]

Hey, I'm having trouble with finding the distance with when a variable is either x or y

e.g

find the distance between each pair of the following points in terms of the given variables

(a,1) (2,3)

[Nato]

Hey, I'm having trouble with finding the distance with when a variable is either x or y

e.g

find the distance between each pair of the following points in terms of the given variables

(a,1) (2,3)

well, you can start off like this. the point (a,1) we can call this (x1, y1) - simply the first pair. then you have the (2,3) - and you can call this (x2,y2).
You can now, apply the formula to find the distance.

Hope this makes sense, feel free to ask more questions

[Only Cheating Yourself]

well, you can start off like this. the point (a,1) we can call this (x1, y1) - simply the first pair. then you have the (2,3) - and you can call this (x2,y2).
You can now, apply the formula to find the distance.

Hope this makes sense, feel free to ask more questions

yea i know used the formula but the answer page has something totally different


(a,1) (2,3)

(2-a)square + (3-1) square

4asuare+4=
square root 4a+a

The book has like square root a-4a+16 i think it was.