Are we allowed to use 'log' in Mathematics (0580) ?

[lol]

Im talking about CIE IGCSE Mathematice (0580) without Coursework, are we allowed to use log function where appropriate? its not in the syllabus so will we still get marks if we get the correct answer?

 

[maheenhemani]

hey wats the log function btw?

 

[M.Talha]

Yes, you Use LOG function. You need to use it some problems in Paper 2.

 

[M.Talha]

Yes, you must use it in some problems in Paper 2.

 

[maheenhemani]

Yes, you must use it in some problems in Paper 2.

wat is it??

 

[aliiiiiiiiii]

which type of questions needlog which leson bcous our school ddnt teach us log

 

[Usman Chughtai]

Yes, you must use it in some problems in Paper 2.

Can u please give am example how to use it ??

 

[XPFMember]

Assalamoalaikum wr wb!
So for this calculator, this is how you'll use the log function:

You have to find m.

2^m = 8

m = log 8 / log 2
= 3

that shows 2^3 = 8

similarly if it was 3^n = 27
then n = log 27/ log 3
= 3

Note: I don't think you're allowed to use this way for working out such questions. The method you're supposed to follow is to make the bases same, and then equate the powers. So what you do is, use this log function and find out 2 to the power of what is 8 (as in the first example..so u know it's 3

so proceed this way:

2^m = 8
2^m = 2^3
therefore m = 3

another example

2^m = 0.125

use log and you'll get -3

now how to show the working, here's how it goes:

2^m = 0.125 (write the decimal number as a fraction using ur calculator.)
2^m = 1/8
2^m = 1/ (2^3)
2^m = 2^-3
therefore m = -3

WARNING: Don't show this on your paper. Just use it to save your time searching and struggling for how to make the bases same.

 

[XPFMember]

Assalamoalaikum wr wb!
If you have this calculator, you may follow the method stated above, and alternatively you can use the other key on the top right below the 'ON' button.
2^m = 8
insert 8 in the bracket, and 2 in the small box, which is the subscript of log...

rest is the same as above.

WARNING: Don't show this on your paper. Just use it to save your time searching and struggling for how to make the bases same.

 

[Usman Chughtai]

Assalamoalaikum wr wb!
So for this calculator, this is how you'll use the log function:

You have to find m.

2^m = 8

m = log 8 / log 2
= 3

that shows 2^3 = 8

similarly if it was 3^n = 27
then n = log 27/ log 3
= 3

Note: I don't think you're allowed to use this way for working out such questions. The method you're supposed to follow is to make the bases same, and then equate the powers. So what you do is, use this log function and find out 2 to the power of what is 8 (as in the first example..so u know it's 3

so proceed this way:

2^m = 8
2^m = 2^3
therefore m = 3

another example

2^m = 0.125

use log and you'll get -3

now how to show the working, here's how it goes:

2^m = 0.125 (write the decimal number as a fraction using ur calculator.)
2^m = 1/8
2^m = 1/ (2^3)
2^m = 2^-3
therefore m = -3

WARNING: Don't show this on your paper. Just use it to save your time searching and struggling for how to make the bases same.

can u plz post a link of past paper which consist of these questions the year and question Number??

 

[aliiiiiiiiii]

oo for this i thougt for someothere sums these sums can be solved without log its easy but thanx v much

 

[Anonymouss]

It is here http://www.xtremepapers.com/papers/...cs (with coursework) (0581)/0581_s07_qp_2.pdf
question 17!

 

[robinhoodmustafa]

Thanks... That was the Q which I was looking for

 

[Usman Chughtai]

It is here http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (with coursework) (0581)/0581_s07_qp_2.pdf
question 17!

Thanx i was looking for it .........

 

[XPFMember]

oo for this i thougt for someothere sums these sums can be solved without log its easy but thanx v much

Yes, no doubt it's easy. But at times, you'd may be have to waste your time finding how to make bases same, etc. Just a backup..you know..

 

[aliiiiiiiiii]

Yes, no doubt it's easy. But at times, you'd may be have to waste your time finding how to make bases same, etc. Just a backup..you know..

yup

 

[iHatesEssays]

You only really need to use log in IGCSE to find answers to exponential algebra, but I don't think CIE will accept it as a valid working because it's beyond the course.
Just use it to check your answer and somehow say you wriggled your way to the answer in the workings.

 

[Suchal Riaz]

using log is not in syllabus. and you need to show working step by step, like making the bases same and then equating exponents. if you just write the answer the examiner would guess that you maybe cheated or used some log so i dont think the marks will be awarded. it is written in instruction on the paper.

WARNING: Don't show this on your paper. Just use it to save your time searching and struggling for how to make the bases same.

You will definitely get marks if you show you working even if you use log. using log is beyond the syllabus but not illegal. It is THE real way to solve variable exponent equations.

 

[My Name]

can some one tell me how to check quadratic equations using tis calculator
FX-82MS
plz

 

[Suchal Riaz]

u can't