Edexcel FP3 June 2015 - Official Thread

Original post by SarahLund

thank you

I just put the answer in your other thread

Reply 423

Original post by TeeEm

I just put the answer in your other thread

Hey TeeEm can you answer the question i asked about eigenvectors

(Original post by chughes17)
You can't use any other value for y and z, you can only do that when you have 3 comparative variables. When solving your 3 simultaneous equations,

x+2z=x

z can only be 0 when you solve by cancelling x's

if you had x=2z and z=2y

then you can set one to whatever you like and figure the other 2 out, but y and z can only take the value 0 in this case

Posted from TSR MobileSo I have to look at the 3 simultaneous and decide what values i can use.

The three equations given were :
x + 2z = x
4y + z = y
5y = z

But if it were like this: [situation 1]

2z = 3x
4y + z = y
5y = z

I could then use any value for x?

What if it were like this : [situation 2]

3x = 0
4y + z + x = y
5y = z

Thanks for Help, this has confuse me for a long time

Reply 424

Original post by ninjasinpjs

Hey TeeEm can you answer the question i asked about eigenvectors

just woke up...
for the next hour or so I am only capable of doing question involving the times tables.

Reply 425

Ilovemaths96

Original post by SarahLund

thank you

no problem :smile:

Reply 426

Original post by TeeEm

just woke up...
for the next hour or so I am only capable of doing question involving the times tables.

Hahaha, 😎 rough night? My brother is still sleep😙

Posted from TSR Mobile

Reply 427

Original post by ninjasinpjs

Hahaha, 😎 rough night? My brother is still sleep😙

Posted from TSR Mobile

night?

I start work at 7 a.m. on Saturdays and finish at 14.00
Then I sleep...

g8.jpg336.9KB

Reply 428

Original post by TeeEm

just woke up...
for the next hour or so I am only capable of doing question involving the times tables.

Ok I will edit my post, take a look at it when you are feeling better, its a 2 marker but i don"t get the concept again :frown:

Posted from TSR Mobile

Reply 429

Hey TeeEm can you answer the question i asked about eigenvectors (2 C)

(Original post by ninjasinpjs)
Hey bro i had a bit of difficulty finding the eigenvector (1) because if any other value was used of y,z instead of x first you get a completely different vector, can you explain why?

(Original post by chughes17)You can't use any other value for y and z, you can only do that when you have 3 comparative variables. When solving your 3 simultaneous equations,x+2z=xz can only be 0 when you solve by cancelling x'sif you had x=2z and z=2ythen you can set one to whatever you like and figure the other 2 out, but y and z can only take the value 0 in this case

Posted from TSR Mobile

So I have to look at the 3 simultaneous and decide what values i can use.

The three equations given were :
x + 2z = x
4y + z = y
5y = z

But if it were like this: [situation 1]
2z = 3x
4y + z = y
5y = z
I could then use any value for x?

What if it were like this : [situation 2]
3x = 0
4y + z + x = y
5y = z

Thanks for Help

(edited 8 years ago)

Reply 430

Part C, after a bit of thought, i assumed that I can come up with 3 equation of planes.

Where A , B , C would be the known point in each of the 3 equations with their respective direction vectors.

So i wanted to ask if these vectors were on the same plane (co-planer), would it mean that there would only be 1 equation of the plane if i were find the equation of the plane for each of the 3 points for this new situation?

Sorry if i'm posting a lot

Reply 431

the reduction questions are so weird, in june 2014 r, you can technically solve it without splitting it up/factorsing but you don't get the form they want, ugh so annoying you realise so late and waste so much time

Reply 432

when you have two plane equations (cartesian) and you have to find an intersecting point, do you always put x/y/z as zero? whenever i put then as 1 i always get the wrong answer, the markscheme always seems to show where one coordinate is zero, is this the way you do it all the time in you have 3 unknowns?

Reply 433

Original post by mmms95

sorry bro, i don't understand what you are saying, can you show me example

Reply 434

Original post by mmms95

you set any one of the three coordinates to any sensible number (zero is good).

two planes cannot possibly intersect at one point, but along a line so the answer is not unique

Reply 435

Original post by TeeEm

you set any one of the three coordinates to any sensible number (zero is good).

two planes cannot possibly intersect at one point, but along a line so the answer is not unique

Original post by ninjasinpjs

sorry bro, i don't understand what you are saying, can you show me example

sorry i meant interesting line, and then point for the line

ahh okay, cause sometimes we have to use that answer in another part, i think i'll just use zero, thanks

Reply 436

Original post by mmms95

sorry i meant interesting line, and then point for the line

ahh okay, cause sometimes we have to use that answer in another part, i think i'll just use zero, thanks

sure

Reply 437

Original post by ninjasinpjs

if i understand what you mean, then i think the answer to your question is yes, if you use different point you still get the same equation of the plane, i.e. there is only one. try visualising it and you'll see there can only be one plane.

Reply 438