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#26 Re: Help Me ! » Can I do this? » 2011-10-06 00:24:02

Thanks a lot Bob.  Good to know i'm improving with Logarithms.

#27 Help Me ! » Can I do this? » 2011-10-05 20:49:38

Deon588
Replies: 3

Hi all.  am I allowed to do this when using the change of base formula?  Thanks in advance

#28 Re: Help Me ! » Probability question which seems a bit unreasonable » 2011-10-02 20:49:46

Hi Bob good to know i'm understanding this correctly...  This came from revision exercises my lecturer created so i'll have to check with her

#29 Re: Help Me ! » Probability question which seems a bit unreasonable » 2011-10-02 19:22:04

I don't think I was totally clear.  So my problem is.  It seems like that would be a very big set?  And not something I would be expected to do in a exam?

#30 Help Me ! » Probability question which seems a bit unreasonable » 2011-10-02 19:19:08

Deon588
Replies: 3

Hi all.  I can't think that I would get a question like this if i'm understanding this correctly
Question:  There are 5 50c coins and 3 20c coins in a tin label the 50c coins f_1 to f_5 and the 20c coins t_1 to t_3.  suppose you put your hand in the tin and take out 3 coins without looking.  Write down the set that represents the event "I have at least one 50c coin amongst the 3 coins that I drew"

#31 Re: Help Me ! » Word problem equation problem » 2011-09-29 10:34:56

Yes I did for the next question I had to find the car's time and it worked perfectly

#32 Re: Help Me ! » Word problem equation problem » 2011-09-29 07:15:45

Bob thanks again, you really have a talent for making things which seem complicated totally understandable I never thought of handling these fractions the same way as fractions without variables.

#33 Re: Help Me ! » Word problem equation problem » 2011-09-29 06:20:50

Thanks a lot Hixy works out fine now.  Bob am I aloud to multiply the


by (x+10) as well?  I'm asking as it's already the denominator of that term?

#34 Help Me ! » Word problem equation problem » 2011-09-29 04:39:42

Deon588
Replies: 19

Hi all.  I can't think of any other way to do this problem any ideas would be much apreciated.

A bus travels 200km at a constant speed a car traveling 10km/h faster than the bus completes the same distance in 1 hour less than the bus, how many hours does the bus take to travel the 200km?

 
When cross multiplying x seems to cancel out. 
Thanks a lot in advance

#35 Re: Help Me ! » Confusing question » 2011-09-29 04:13:34

Thanks a lot Bob and Bobbym.  I have done this many times before but the way the question was written confused me a bit

#36 Re: Help Me ! » Confusing question » 2011-09-28 22:02:29

Hi Bob.  Differential calculus is not part of my course this year at all.  So I can find x either by completing the square or

?
If i'm asking for help too much lately please let me know.  I have exams in 3 weeks so trying to get everything cleared up before the exam.
Thanks

#37 Re: Help Me ! » Confusing question » 2011-09-28 19:33:41

Hi Bob.  I did exactly that up to the point

 
Thanks

#38 Re: Help Me ! » Confusing question » 2011-09-28 11:00:09

Hi Bob I have the parabola and lines equations.  So to find the maximum I subtracted the line's equation from the parabola's equation but from here i'm not sure.

#39 Help Me ! » Confusing question » 2011-09-28 09:31:35

Deon588
Replies: 10

Hi.  I am a bit confused with this question the question is "Find the coordinates of M when BA is a maximum"  Should I subtract the straight line from the parabola and then

I don't understand how BA has any effect on M?  Doesn't M just stay where it is on the x-axis?
Thanks a lot in advance

#40 Re: Help Me ! » Equation problem » 2011-09-28 08:30:28

I had some internet problems so havn't been online.  Bob lol no worries and thanks a lot That answer makes a lot of sense I definitely learned something new.

#41 Re: Help Me ! » Equation problem » 2011-09-25 06:35:24

Thanks a lot for all the answers.  Bob when you have

as the denumerator doesn't that become 2 and not

#42 Re: Help Me ! » Equation problem » 2011-09-24 23:09:05

Sorry I tried entering the LaTeX.  Any idea where my LaTex mistake was?
Thanks

#43 Re: Help Me ! » Equation problem » 2011-09-24 23:06:59

Hi Bob.  Thanks a lot that was a very nice detailed explanation.  The only part I don't totally understand is where you changed the base

#44 Re: Help Me ! » Equation problem » 2011-09-24 04:52:40

Should I do it like this? 

  Should the domain be >0?  Thanks again.

#45 Re: Help Me ! » Equation problem » 2011-09-24 00:46:19

Sorry for not being totally clear annonimnystify.  The question is write the domain of f(x) and solve the equation.  Zetafunc do you mean break it up like this log_2(x-4)=log_4((x-8) sorry for writing it like this, I don't know much about LaTeX yet...  If this is the way to go how would the change of base step look?  should it be log_2/log_2(x-8)?  Thanks a lot

#46 Help Me ! » Equation problem » 2011-09-23 20:21:55

Deon588
Replies: 18

Hi all.  I have no idea if i'm doing this the right way, If I am where do I go from here?  Thanks in advance

#47 Re: Help Me ! » Finding the y-coordinate of the vertex of a parabola » 2011-06-15 05:42:22

Thanks a lot bobbym.  Didn't see your post at first as it was on page 2.  g(x):y=-1/2x so then x=-5 which makes more sense as p<q and q=(-4,0).  I totally forgot what to do if I have e.g x^2 +5x.  So x(x+5)
x=0  or  x=-5

#48 Re: Help Me ! » Finding the y-coordinate of the vertex of a parabola » 2011-06-15 03:08:13

Hi.  I am posting this here because it has to do with the same graph.  I have to find the point P.  As this is one of the points of intersection of g(x) and f(x) I tried solving the system of equations.  At the end I got x^2+5x=0 and I didn't know how to proceed.  One of my previous questions was find the equation of the line which is paralel to g and passes through the point R Which is (-2,-2)  which I got as y=-1/2x-3.  Can I solve the system of equations of that line and f(x) and then subtract 3 from the x coordinate and add 3 to the y-coordinate?

#49 Re: Help Me ! » Finding the y-coordinate of the vertex of a parabola » 2011-06-14 23:22:29

Thanks for the quick responses.  Bob thanks a lot for posting that detailed explanation anyhow because I still was a bit unsure but now I know where my mistake lies.  I am studying from home at the moment and have a class with a tutor once a week which makes it very difficult when I get stuck somewhere.

#50 Re: Help Me ! » Finding the y-coordinate of the vertex of a parabola » 2011-06-14 22:48:46

Congratulations Bob!!!  I am still doing something wrong as my solution to the equation always is concave down even though I can see from the graph that it's concave up.  Sorry I don't usually take this long to understand something but parabolas is something totally new to me.

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