O-Level Additional Math

[SKT]

Answer obtained from a Trigo question as such:

sin x = 1/2 or sin x = 1
x = 30°, 150° or x = 90° --(1)
x = 30°, 90°, 150° --(2)

Should we stop at (1) or (2)?

TIA.

[ADoc]

SKT:

Answer obtained from a Trigo question as such:

sin x = 1/2 or sin x = 1
x = 30°, 150° or x = 90° --(1)
x = 30°, 90°, 150° --(2)

Should we stop at (1) or (2)?

TIA.

Hi there! Stopping at either is acceptable. However, in terms of mathematical presentation of coherence & convention, we usually write, x = 30°, 90° or 150° as a concluding statement.

Hope this helps. Cheers!

[elkniwt]

Hello,


Thanks to ADoc, iFruit and atutor2001 for your comments and advices !!
:thankyou:

Sorry I sound so exaperated in my posting. I just felt sorry to see her so upset and her eyes reddening when she told me. She got 11 out of 20 for the test, if not for this qn and another qn, she could have gotten 17. This other qn also as frustrating cos she got 0 out of 4 though she proved it correct. Teacher says she did not understand how my niece arrived at the answer. Though after explaining to the teacher, she could understand, she still did not give her the marks.

Appreciate this forum as there are many here to help and give advices.

Thanks!

[skyjuice]

Any one has a tuition centre to recommend for Sec 2 Math? Right now DS is borderline pass case but need a quick jump to at least 70 to be offered a Double Science class next yr.


We put up in Bukit Merah area but don’t mind travelling a bit if the teacher is gd. I just checked Learning Lab and its fees are $900+ a term. Is this the going rate for Sec Math classes?

[YLH88]

skyjuice:

Any one has a tuition centre to recommend for Sec 2 Math? Right now DS is borderline pass case but need a quick jump to at least 70 to be offered a Double Science class next yr.


We put up in Bukit Merah area but don't mind travelling a bit if the teacher is gd. I just checked Learning Lab and its fees are $900+ a term. Is this the going rate for Sec Math classes?

You may want to check out with maths hub at

http://www.mathshub.com.sg/

[elkniwt]

Hello,


Helping my niece ask this qn:

Find an expression f(x) such that d/dx [f(x)] = 1/(xlnx)

Thanks for help.

[jieheng]

elkniwt:

Hello,


Helping my niece ask this qn:

Find an expression f(x) such that d/dx [f(x)] = 1/(xlnx)

Thanks for help.

d/dx [f(x)] = 1/(xlnx)

= (1/x ) / (ln x)

f(x) = ln (ln x) + c (Ans)

[Acsian]

hello can i get help for the following algebra question…


(m+2)/3 + 2(m-5)/4

Sorry new to algebra solved untill 10m-22 / 12 stuck after it

[jieheng]

Acsian:

hello can i get help for the following algebra question......


(m+2)/3 + 2(m-5)/4

Sorry new to algebra solved untill 10m-22 / 12 stuck after it

(m+2)/3 + 2(m-5)/4

= [(m+2)*4]/(3*4) + [2(m-5)*3]/(4*3)

= [ (4m+8)+ (6m-30) ] / 12

= (10m-22) / 12

= (5m-11) / 6 (Ans)

[Acsian]

jieheng:

Acsian:

hello can i get help for the following algebra question......


(m+2)/3 + 2(m-5)/4

Sorry new to algebra solved untill 10m-22 / 12 stuck after it

(m+2)/3 + 2(m-5)/4

= [(m+2)*4]/(3*4) + [2(m-5)*3]/(4*3)

= [ (4m+8)+ (6m-30) ] / 12

= (10m-22) / 12

= (5m-11) / 6 (Ans)

actually the answer in my math handbook is 5m-5/6 and i typed the equation wrongly :oops:

correct equation

(m+2)/3 + 2(m-5)/4 +1