PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.
EconsPhDTutor
OrangeBelt Posts: 39
Joined: Sat Jan 23,
Total Likes:1

linden2000 wrote: Thank you!
Understand it now. Should line 1 be 2n instead of 2n^2?
Hello linden2000,

Yes you are right. I am sorry, that was my mistake. I have corrected it. Please see the same PDF link again where my mistake is now corrected.

KSP2013777
OrangeBelt Posts: 92
Joined: Fri Dec 28,

Can somebody please help me on this question. It says to differentiate it. I used quotient rule but become so confused. I tried many times but still cannot get the answer. Thank you.

jieheng
BrownBelt Posts: 613
Joined: Thu Mar 24,
Total Likes:3

KSP2013777 wrote:Can somebody please help me on this question. It says to differentiate it. I used quotient rule but become so confused. I tried many times but still cannot get the answer. Thank you. KSP2013777
OrangeBelt Posts: 92
Joined: Fri Dec 28,

Thank you jieheng.
My answer is same like yours. But book ans key is 3/(3x-2) + 1/(4-x).
Maybe ans key is wrong?

jieheng
BrownBelt Posts: 613
Joined: Thu Mar 24,
Total Likes:3

KSP2013777 wrote:Thank you jieheng.
My answer is same like yours. But book ans key is 3/(3x-2) + 1/(4-x).
Maybe ans key is wrong?
Answer key is also correct as 3/(3x-2) + 1/(4-x) = 10 /[(3x-2)(4-x)]

sr129
KiasuNewbie Posts: 1
Joined: Sat Mar 12,

Can someone help me with these questions? jieheng
BrownBelt Posts: 613
Joined: Thu Mar 24,
Total Likes:3

sr129 wrote:Can someone help me with these questions?  questionable_i
BrownBelt Posts: 535
Joined: Sat Oct 10,
Total Likes:1

Can anyone help me with these questions?

1. The straight line 3y=6-2x meets the curve (2x+1)^2+6(y-2)^2-49=0 at the points P and Q. Find the point P and Q and leave your answer in surd form.

2. α and β are roots of the equation x^2+2x=h. The quadratic equation 8x^2-6x+k=0 har roots of (1-α)/α and (1-β)/β. Find the values of h and k.

3.Find the range of values of k for which the expression 2(k-3)x-25-x^2 is always negative for all real values of x.

I need it ASAP. kennethTutor
OrangeBelt Posts: 39
Joined: Mon Jul 13,
Total Likes:2

questionable_i wrote:Can anyone help me with these questions?

1. The straight line 3y=6-2x meets the curve (2x+1)^2+6(y-2)^2-49=0 at the points P and Q. Find the point P and Q and leave your answer in surd form.

2. α and β are roots of the equation x^2+2x=h. The quadratic equation 8x^2-6x+k=0 har roots of (1-α)/α and (1-β)/β. Find the values of h and k.

3.Find the range of values of k for which the expression 2(k-3)x-25-x^2 is always negative for all real values of x.

I need it ASAP. For Q1, basically we solve simultaneous equations by using Substitution method. I did not get any surds for my answer, so you might want to check the question again.

Solution: http://imgur.com/OIhjQ0W

For Q2, we find the Sum of Roots (SOR) and Product of Roots (POR) for both equations. We use the SOR and POR to find the values of the unknowns h and k.

Solution P1: http://imgur.com/zkog0A5
Solution P2: http://imgur.com/L552BGx

For Q3, we use discriminant b^2 - 4ac < 0, as the curve is always negative. This means that the curve does not cut the x-axis, therefore there are no real roots.

Solution: http://imgur.com/sbKZD3A

jazzie76
KiasuNewbie Posts: 1
Joined: Wed Mar 16,