O-Level Additional Math

PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.
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Angel88
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Re: O-Level Additional Math

Post by Angel88 » Sun Apr 03, 2016 5:19 pm

anyone can help to solve this question? Thank you! Image

Eddow
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Re: O-Level Additional Math

Post by Eddow » Sun Apr 03, 2016 6:34 pm

Angel88 wrote:anyone can help to solve this question? Thank you! Image
Give you a guide to start. :smile:

Move one item to the right.
Take lg both side.
Use power law to bring the power down.
Expand and you will be able to group the lg x together and solve.
Try it :smile:

Eddow
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Re: O-Level Additional Math

Post by Eddow » Sun Apr 03, 2016 6:44 pm

KSP2013777 wrote:Can somebody pls help me with this question?
Image
Thank you.
HI,

Firstly you have to read carefully. Qn is not asking for stationary point of CURVE !
It is asking for the stationary value for the GRADIENT FUNCTION. :scared:

Solution :
So you need to differentiate the GRADIENT, then equate it to zero for stationary value :smile:
Try it, should be ok now :smile:

KSP2013777
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Re: O-Level Additional Math

Post by KSP2013777 » Mon Apr 04, 2016 10:07 pm

Yes, thank you, Eddow. Got the answer now.

Can you help me with another one.
Image

My ans is e^(3/2), but ans key is 1/e^(1/2). Pls help. Tks

kennethTutor
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Re: O-Level Additional Math

Post by kennethTutor » Tue Apr 05, 2016 4:05 am

KSP2013777 wrote:Yes, thank you, Eddow. Got the answer now.

Can you help me with another one.
Image

My ans is e^(3/2), but ans key is 1/e^(1/2). Pls help. Tks
Hello. I think you might have made a mistake in the differentiation.

Anyways I suggest you try to simplify the expression (ln part) before differentiating. It will make the differentiation less tedious.


Solution: http://imgur.com/7viZpYS


happyheart
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Re: O-Level Additional Math

Post by happyheart » Tue Apr 05, 2016 7:53 pm

Image Hi, can anyone help to explain these 2 questions?Thank you. Sorry the upload pic is not up to standard.

Eddow
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Re: O-Level Additional Math

Post by Eddow » Wed Apr 06, 2016 10:42 pm

happyheart wrote:Image Hi, can anyone help to explain these 2 questions?Thank you. Sorry the upload pic is not up to standard.
Image
Image
Last edited by Eddow on Wed Apr 06, 2016 10:51 pm, edited 1 time in total.

questionable_i
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Re: O-Level Additional Math

Post by questionable_i » Sat Apr 16, 2016 8:22 pm

Can anyone please help me with these questions,
1. 9^y+5(3^y-10)=0
2. 3^2x=16-2(3^x+1)
3. 2^2x=2^x+1+15
Thank you

Eddow
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Re: O-Level Additional Math

Post by Eddow » Sat Apr 16, 2016 11:56 pm

questionable_i wrote:Can anyone please help me with these questions,
1. 9^y+5(3^y-10)=0
2. 3^2x=16-2(3^x+1)
3. 2^2x=2^x+1+15
Thank you
A rough guide... Use suitable substitution for all the Qn.
1. Let u = 3^y
2. Let u = 3^x
3. Let u = 2^x
Then you can carry on solving using quadratic equation.
Try :smile:

questionable_i
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Re: O-Level Additional Math

Post by questionable_i » Tue Apr 19, 2016 7:40 pm

Eddow wrote:
questionable_i wrote:Can anyone please help me with these questions,
1. 9^y+5(3^y-10)=0
2. 3^2x=16-2(3^x+1)
3. 2^2x=2^x+1+15
Thank you
A rough guide... Use suitable substitution for all the Qn.
1. Let u = 3^y
2. Let u = 3^x
3. Let u = 2^x
Then you can carry on solving using quadratic equation.
Try :smile:
Thank you so much.

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