Friday, 15 February 2013

Answers for Indices A02a and Revision Worksheet (E Math)

Dear all

Here are the answers for your checking for the worksheets.

Indices A02a

Revision Worksheet (E Math)

Tuesday, 5 February 2013

Common Mistakes of Indices ( Harindrar | Saishwar )

Leaving answer in index form even though question does not ask to.
EG: Leaving 216^1/3 as an answer instead of 6

Not putting the question into index form, hence getting stuck and being unable to carry on.
EG: 144 = X^2
        144 = 12^2

Leaving answer in surd or indices form when the question says otherwise.
leaving answer as 3^1/2 when question asks for surd form
leaving answer as Squareroot(3) when question asks for indices form

Thank you,
Harindrar and Saishwar.

Common Errors

Common Errors
1. Unable to remember all 10 rules.
2. Unable to use multiple rules at once.
3. Careless.

1. Practice more.
2. Try to memorize the 10 rules.
3. Double check work.

Common Errors and Tips (Keming, Isaac, Ying Liang)

Common Errors

1) Confused with how to expand the brackets for indices 
2) Using guess and check to obtain answers
3) Unable to obtain answers for sums with the same indices 


1) Double check using a calculator and make sure it tallies 
2) Think properly and nicely without getting angry and panic in the process as panicking will only yield useless and marks-reducing results
3) Getting used to the laws of indices

3 Common Errors (Indices) by Imanni and Harriz

Common Errors

1) Confusion of the 10 laws and how they co-relate with each other.
2) Confusion of negative indexes and how they can be solved.
3) Deriving the unknown bases and powers.


1) Check for errors in calculation whenever you are stuck or skip the question then come back to it to check.
2) Take your time when attempting a question so as to minimize errors during calculation.
3) Revise at home so that you are familiar with what you learnt.

3 Common Errors

1.Negative indices
1 / 2 = 2^-1
2.Squaring negative integers

3.Changing the base

3 Common Errors (Indices)

Iffah (05) & Danish (15)

3 Common Errors & How to Avoid Them

1. Splitting up integers to their base+index.

For example, 4^x = 32.
We need to first split up 4 and 32 to their base form, that is 2^2 and 2^5, for 4 and 32 respectively.

Hence, (2)^2x = 2^5
2x = 5
x = 2.5

You can try looking at common bases that both numbers have.

2. Negative indices.

a ^ (-n) = 1 / a^n

Don't get confused! :) Know that for every negative index, you move it either UP or DOWN of the fraction. Like.....

-(3 ^2) x 3 ^(-3)
= -9 [THE SQUARE BELONGS ONLY TO 9, AND NOT TO -9] x 1 / 3^3
= -9 x 1/27
= -9/27
= -1/3
= - (1/3)

You can make sure you follow the BODMAS law first.

3. Multiplication law. a^b x a^c = a ^(b+c)

For example,

3 ^(1/2) x 3 ^(1/2)
= 3 ^ (1/2 + 1/2)
= 3 ^ 1
= 3.

In this case, it is not 1/2 x 1/2, but instead 1/2 + 1/2! Multiplication law (same base!)


PS. Danish didn't do anything omfg

Common Errors of Indices and Tips (Jonathan, Yu Tao, Kenneth)

Common Errors

1) Confusion of multiplication/division and addition of the indices.
2) Distribution of the bracketed index.
3) Conversion of index form into surd form, vice versa.


1) Double check for arithmetic errors after completing the question or when stuck.
2) Relax, take your time and don't rush when attempting the question.
3) Familiarise yourself with the rules and laws of indices and surds.