KiasuParents - Parenting in Singapore

Goodluck889 wrote:Can someone help me with this maths question?
Factorise 144z^2 + 121.

It can't be factorise unless it is a minus(-) sign

Goodluck889 wrote:Can someone help me with this maths question?
Factorise 144z^2 + 121.

This has a pair of complex roots. So, it is
(z + 11/12 i)(z - 11/12i), where i = sqrt(-1) is the imaginary number.

This is not in the O level syllabus, only in the A level syllabus.

How to solve this compound interest problem!
A man deposited 2,000 into a bank that paid compound interest of 3.28% compound half yearly. He continued depositing $2,000 into the bank every six months.Calculate the amount of money he had after he made his fifth deposit of $2,000,giving your answer correct to the nearest cent.

I need help to solve this question in an easy way acceptable for O level. Also I have a doubt about whether the interest given(3.28%) is annual interest or half year interest as in the question,it is not mentioned clearly.
Thanks

Can help me with this math question?
The result "lg xy = lg x + lg y" is not always true!
1a) Give a pair of values of x and y such that the result will not hold.
Similarly, give values of x,y and r such that the following results fail:
1b) lg x/y = lg x - lg y
1c) lg x^r = r lg x

I understand the condition that x and y must be positive number for lg to be defined and r must be real number.
can you tell me how to answer the above question.



Thank you

Can someone help me with this question?

thank you

Volcano123 wrote:Can someone help me with this question?

thank you

Answer for

Part i) is 2 + 2√2 and Part ii) is 2 ± 2√2

Dear jieheng,
Thank you very much for your help greatly.

Thank you very much Jieheng for your help .
part i is only the positive answer bcos log of -ve number is undefined.
part ii has both the positive and negative answer.
Thank you once again. You are marvelous.

Volcano123 wrote:Thank you very much Jieheng for your help .
part i is only the positive answer bcos log of -ve number is undefined.
part ii has both the positive and negative answer.
Thank you once again. You are marvelous.

Hi Volcano123 '

You are right .

The working for both parts i) and ii) are the same but the negative answer for part i) should be rejected due to log₂ x

student101 wrote:How to solve this compound interest problem!
A man deposited 2,000 into a bank that paid compound interest of 3.28% compound half yearly. He continued depositing $2,000 into the bank every six months.Calculate the amount of money he had after he made his fifth deposit of $2,000,giving your answer correct to the nearest cent.

I need help to solve this question in an easy way acceptable for O level. Also I have a doubt about whether the interest given(3.28%) is annual interest or half year interest as in the question,it is not mentioned clearly.
Thanks

It is rather ambiguous, I'm leaning towards the interest as per annum, otherwise they might as well word it such that the deposits are made every year and ask the for the amount after the 5th year.

Breaking down the timeline might be the easiest way to explain to a student.

After 1st deposit : 2000
After 2nd deposit : 2000 x 1.0164 + 2000 = 4032.8
After 3rd deposit : 4032.8 x 1.0164 + 2000 = 6098.9379
After 4th deposit : 6098.9379 x 1.0164 + 2000= 8198.961
After 5th deposit : 8198.961 x 1.0164 + 2000= 10333.42