# Mathematics: Post your doubts here!

#### blymphocytes

In order to apply logarithm on 1/y^3 the derivative of y^3 should be present in the numerator then we can use it.
Oh ok.....so for example it was 2/y^3.........we could write this as 2ln(y^3)

#### Hamnah Zahoor

Oh ok.....so for example it was 2/y^3.........we could write this as 2ln(y^3)
No ....derivative of y^3 is 3y^2 this should be present.

#### blymphocytes

No ....derivative of y^3 is 3y^2 this should be present.
So 3y^2 should be the numerator?.......Always??

#### blymphocytes

So 3y^2 should be the numerator?.......Always??
Liek for all denominators....the numerator should be a derivative in order to use ln?

#### Hamnah Zahoor

Liek for all denominators....the numerator should be a derivative in order to use ln?
correct

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#### blymphocytes

For remembrance it's given on the formula sheet
Thanks.....once again!!!

#### fourtris46

can anyone please send me the working of feb19 q3?

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#### fourtris46

in the last step, why did you multiply and divide with square root 2 ?

#### Hamnah Zahoor

in the last step, why did you multiply and divide with square root 2 ?
Just to simplify it more ..it's not a necessity .
And I just read the question it says no need to simplify the answer thus you can give the answer without multiplying and dividing by square root 2.

#### fourtris46

Just to simplify it more ..it's not a necessity .
And I just read the question it says no need to simplify the answer thus you can give the answer without multiplying and dividing by square root 2.
thank u so muchhhh

#### Hamnah Zahoor

Can someone possibly show me the working of question 5, feb march paper 32 2019?

#### Hamnah Zahoor

Can someone possibly show me the working of question 5, feb march paper 32 2019?
I solved it rougly I hope it is understandable

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