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Re: O-Level Additional Math
Posted: Sun May 22, 2016 6:51 pm
by kennethTutor
KSP2013777 wrote:Thank you, Kenneth Tutor.
Can you help me with another question, Please?
Thank you.
The fraction is an improper fraction, since the degree of the numerator is 4 while the degree of the denominator is 3.
Perform long division first. You obtain x + (9 - 3x^2)/(x^3 + 3x)
Finally perform partial fraction decomposition on (9 - 3x^2)/(x^3 + 3x)
Final ans should be: x + 3/x - 6x/(x^2 + 3)
Re: O-Level Additional Math
Posted: Sun May 22, 2016 7:34 pm
by kennethTutor
questionable_i wrote:Can anyone help me?
in advance.
Q1) A function f is defined by f(x)=|x^2-3x|. Find the values of x for which f(x)=x-3.
Q2) Find the
x-coordinates of the
points of intersection of the
curve y=|16-x^2| and the
line y=33.
Q3) Find the x-coordinates of all the points at which the graph of y=|x^2-9|-5 meets the x-axis.
For Q1, first we sub one equation into another.
|x^2 - 3x| = x - 3
For modulus, there is the positive and negative side.
For the positive (and removing the modulus),
x^2 - 3x = x - 3
x^2 - 4x + 3 = 0
(x - 3)(x - 1) = 0
x = 3 or x = 1
For the negative,
x^2 - 3x = -(x - 3)
x^2 - 3x = -x + 3
x^2 - 2x - 3 = 0
(x - 3)(x + 1) = 0
x = 3 or x = -1
So the values of x are: -1, 1 or 3
You can use the same approach for Q2 and Q3. For Q3, the equation of x-axis is y = 0.
Re: O-Level Additional Math
Posted: Mon May 23, 2016 8:30 pm
by KSP2013777
Please, can somebody help me solve this question?
Is it tangent to curve means Discriminant =0? But how to use Discriminant if there is ln x? Please help. Thank you
Re: O-Level Additional Math
Posted: Mon May 23, 2016 8:39 pm
by PiggyLalala
KSP2013777 wrote:Please, can somebody help me solve this question?
Is it tangent to curve means Discriminant =0? But how to use Discriminant if there is ln x? Please help. Thank you
this question is not about discriminant = 0. Always remember, discriminant is only for quadratic equation. This is a differentiation question.
So differentiatate and set dy/dx = gradient of the tangent. Find x. Then the y coordinate. Lastly the value of k. Give it a try. 加油。。
Re: O-Level Additional Math
Posted: Tue May 24, 2016 9:29 am
by KSP2013777
Thank you, piggy lalala. Can get my answer now.
Re: O-Level Additional Math
Posted: Thu Jun 02, 2016 9:25 pm
by KSP2013777
I need help for this question. Can somebody please help me.
Thank you.
Re: O-Level Additional Math
Posted: Sat Jun 04, 2016 7:50 pm
by questionable_i
Can anyone help me with this question? Thank you.
1) By expressing each of the following equations in the form a^x=b where a and b are real numbers, take logarithms to solve for x.
(a) 2^(x+1)=3^x
(b)
Re: O-Level Additional Math
Posted: Sun Jun 05, 2016 10:02 am
by PiggyLalala
KSP2013777 wrote:I need help for this question. Can somebody please help me.
Thank you.
Re: O-Level Additional Math
Posted: Sun Jun 05, 2016 10:29 am
by PiggyLalala
questionable_i wrote:Can anyone help me with this question? Thank you.
1) By expressing each of the following equations in the form a^x=b where a and b are real numbers, take logarithms to solve for x.
(a) 2^(x+1)=3^x
(b)
Re: O-Level Additional Math
Posted: Wed Jun 22, 2016 10:29 am
by KSP2013777
Can somebody pls help me with this question?
Tks