## O-Level Additional Math

### Re: O-Level Additional Math

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

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

### Re: O-Level Additional Math

HI,KSP2013777 wrote:Can somebody pls help me with this question?

Thank you.

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.

Solution :

So you need to differentiate the GRADIENT, then equate it to zero for stationary value

Try it, should be ok now

- KSP2013777
- OrangeBelt
**Posts:**92**Joined:**Fri Dec 28,

### Re: O-Level Additional Math

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

Can you help me with another one.

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

Can you help me with another one.

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

- kennethTutor
- OrangeBelt
**Posts:**39**Joined:**Mon Jul 13,**Total Likes:**2

### Re: O-Level Additional Math

Hello. I think you might have made a mistake in the differentiation.KSP2013777 wrote:Yes, thank you, Eddow. Got the answer now.

Can you help me with another one.

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

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
- KiasuGrandMaster
**Posts:**1304**Joined:**Thu Oct 07,**Total Likes:**4

### Re: O-Level Additional Math

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

### Re: O-Level Additional Math

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

Last edited by Eddow on Wed Apr 06, 2016 10:51 pm, edited 1 time in total.

- questionable_i
- BrownBelt
**Posts:**535**Joined:**Sat Oct 10,**Total Likes:**1

### Re: O-Level Additional Math

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

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

### Re: O-Level Additional Math

A rough guide... Use suitable substitution for all the Qn.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

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

- questionable_i
- BrownBelt
**Posts:**535**Joined:**Sat Oct 10,**Total Likes:**1

### Re: O-Level Additional Math

Thank you so much.Eddow wrote:A rough guide... Use suitable substitution for all the Qn.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

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