PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.
Angel88
OrangeBelt
Posts: 40
Joined: Sun Jul 28,

anyone can help to solve this question? Thank you!

Eddow
GreenBelt
Posts: 186
Joined: Sun Oct 11,
Total Likes:1

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

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

Eddow
GreenBelt
Posts: 186
Joined: Sun Oct 11,
Total Likes:1

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

Thank you.
HI,

Firstly you have to read carefully. Qn is not asking for stationary point of CURVE !

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,

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

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

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

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

Eddow
GreenBelt
Posts: 186
Joined: Sun Oct 11,
Total Likes:1

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

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
GreenBelt
Posts: 186
Joined: Sun Oct 11,
Total Likes:1

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

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

Eddow wrote: