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Yes that was also the next question in the exam paper I did, worked out perfectly at the end

Hi Bobbym any idea where I made a mistake?

Thanks a lot

**Deon588**- Replies: 12

Hi all. I think i'm making a mistake somewhere as the matrix I get after multiplying doesn't seem to be invertible and the next question is to find A^-1. Is this the right way to do this?

Thanks in advance

Thanks Bob your explanation once again makes me able to move forward!!!

**Deon588**- Replies: 3

Hi all i'm not sure at all how to proceed with this problem, I need to find the principal argument of z but not sure how to go about it... After googleing I found (theta +2k(pi) =x/r so if I understood correctly (theta +2k(pi) =1/2?

Thanks in advance

I made a big mistake, I have a newer edition of the prescribed book which has a chapter on eigen values added. I just checked on my study guide and see it's only the basic complex number theory that I need to study

Thanks for taking a look at it anyhow

Deon

Hi Bob

Yes of course I attached 3 questions

Thanks

I have another question for you:) I recently lost a month of studying because of medical issues... The only part of Linear algebra I haven't covered is the chapter dealing with eiggen values (not sure if I spelled that correctly) I see that some complex number skills are required for that chapter and i've never done complex numbers before. I went through the past 3 years exam papers of my university and it seems like eigen vallues rarely appears and if it does it counts maybe 7/100 marks. i'm writing Linear algebra on 23/10 so not much time left. So right now i'm not sure at all whether just to forget about the eigen values and focus on the other work or try to learn some basic complex number theory and do the eigen value chapter as I have 4 other subjects this semester... What would you recommend I do? would it be possible to learn enough about complex numbers to use in a elementary linear algebra course?

Thanks

the emoticon is supposed to be =

Good to know you're still on these forums, I remember you helped me get past a lot of challenging problems last year.

I think so, is this the way to do this? Sorry for the bad notation i'll have to go over the LaTeX post again...

x=p+t(q-p)

(x,y,z)=(2,4,-1)+t((5,0,7)-(2,4,-1))

(x,y,z)=(2,4,-1)+t(3,-4,8)

x=2+3t

y=4-4t

(x,y)=(2+3t,4-4t)

Thanks a lot

**Deon588**- Replies: 10

Hi all I recently started linear algebra and my prescribed book seems to require some 3-dimensional geometry knowledge which i've never touched... Any idea how to go about this?

Let L be the line that passes through the points P(2,4,-1) and Q(5,0,7) Determine the point of intersection of L and the x-y plane

Should the z-coordinate be 0 because the question only mentions the x-y plane?

Thanks

Hi Bobbym I think that's a bit above my level at this stage...

Thanks anyhow for the reply

Can you please show me what you mean by I should group stuff?

Should I break it up like

**Deon588**- Replies: 7

Hi all I have no idea how to start this equation the exponential equations I have done so far were all more or less the same (becomming a quadratic equation which made it very easy to solve X)

How do I start this? should I somehow devide everything by 3?

Thanks in advance

Thanks a lot.

**Deon588**- Replies: 2

Hi all. Does this look ok? I didn't pay much attention to this work during the year and writing maths tomorrow... Is there a way to simplify this further? and would it be ok to leave it as a logarithm and just write grams afterwards?

We also write coordinates on the cartetian plane as (x;y) and not (x,y)

Bob thanks a lot for that very detailed explanation, as usual u completely cleared it up for me:).

Hi Bob. That's the part which confuses me. isn't

Thanks a lot for checking

So it will take Machine B 4 hours to fill the bottles?

Thanks a lot Bobbym. so

Thanks in advance

**Deon588**- Replies: 11

Hi all. Am I doing this correctly?

Question

In a factory 2 different machines A and B are used to fill bottles When the machines work together they fill the bottles in 2 hours. Machine A works twice as fast as machine B, how long does it take machine B to fill the bottles when it works alone? What i've done: