Mathematics: Post your doubts here!

[1357913579]

iam getting the f inverse g wrong maybe ms is wrong or i have forgotten some of the As so maybe because of that but i have tried my best to explain and make you understand so here are the files

 

[CaptainDanger]

iam getting the f inverse g wrong maybe ms is wrong or i have forgotten some of the As so maybe because of that but i have tried my best to explain and make you understand so here are the files

That is what made me stop posting my answers!!! I get the same answer as yours for the inverse part...

 

[XPFMember]

Assalamoalaikum!

u attached 3 images ...i'm confused...
anyway with the second image abt that inverse one...is the answer x^2 - 2x - 3 = 0

 

[CaptainDanger]

Assalamoalaikum!

u attached 3 images ...i'm confused...
anyway with the second image abt that inverse one...is the answer x^2 - 2x - 3 = 0

Walikum Salaam!

Its x^2-3/2... In marking scheme its 1/2(x^2-3)

 

[XPFMember]

The term (x^2 - 3) is in the denominator or numerator in the second case?

 

[CaptainDanger]

Denominator...

1 ÷ 2(x^2 - 3)

 

[XPFMember]

may i know which year is this?

 

[1357913579]

even i want to know which year is that i think ms is wrong

 

[1357913579]

i attached 3 because there were 3 question so solved in 3 images

 

[CaptainDanger]

Its the last question. Even f inverse of x is something else in marking scheme...

http://www.xtremepapers.com/CIE/index.php?dir=International A And AS Level/9709 - Mathematics/&file=9709_s11_qp_11.pdf

http://www.xtremepapers.com/CIE/index.php?dir=International A And AS Level/9709 - Mathematics/&file=9709_s11_ms_11.pdf

 

[CaptainDanger]

I figured it out... Marking scheme is wrong once again! Examiner report has the correct answer as ours...

 

[1357913579]

oh good, good done to look in the examiner report.

 

[elbeyon]

That is why I was getting wrong answers(according to marking scheme) during my previous attempts.

 

[elbeyon]

Can anyone help me in the range topic of functions(Paper 1) ?
Can someone please upload effective notes in that topic.
Please help me.

 

[Gémeaux]

Can anyone help me in the range topic of functions(Paper 1) ?
Can someone please upload effective notes in that topic.
Please help me.

here's a video on that topic.
http://www.examsolutions.co.uk/math...nctions/functions/domain-range/tutorial-1.php
P.S. all of his videos are amazing, i understood half the topics frm them rather than frm ma teacher.

 

[usmanmahmood]

Can someone please Solve any one of these 3 questions of Differentiation? I'm having problem solving questions where they ask to "Find a and b" ...

 

[abcde]

Can someone please Solve any one of these 3 questions of Differentiation? I'm having problem solving questions where they ask to "Find a and b" ...

View attachment 3254

AoA! I pick 7! Here:
y = 2x^3 + ax^2 + b
=> dy/dx = 6x^2 + 2ax
At the stationary point, dy/dx = 0.
=> 6(-3)^2 + 2a(-3) = 0
=> 6a = 54
=> a = 54/6 = 9
Insert these values into the equation given to find b.
19 = 2(-3)^3 + 9((-3)^2 + b
=> b = 19 - 27 = -8.
Therefore, a = 9 and b = - 8.

To determine whether it's maximum or minimum,
d^2y/dx^2 = 12x + 2a = 12(-3) + 2(9) = - 36 + 18 = - 18, which is less than zero. Therefore, this stationary point is a maximum.

 

[CaptainDanger]

I need some GOOD explanation to Q6 iii part? Anyone? If possible, solve it with as many ways as possible?

9709_w04_qp_1.pdf

9709_w04_ms_1.pdf

 

[abcde]

I need some GOOD explanation to Q6 iii part? Anyone? If possible, solve it with as many ways as possible?

9709_w04_qp_1.pdf

9709_w04_ms_1.pdf

AoA!
Q6) (iii) f(x) = 3 + 2 sin^2 x
Firstly, identify the maximum and minimum values of sin^2 x. The maximum would be 1 since the maximum of sin x is 1 and squaring that gives 1, too. The minimum of sin x is - 1 but squaring that would again give the maximum of 1! So the minimum of sin^2 x is 0. Put these values into the function.
Maximum value of f(x) = 3 + 2(1) = 5
Minimum value of f(x) = 3 + 2(0) = 3
Hence, the given range.

 

[CaptainDanger]

^ I don't get "maximum of sin x is 1"? And "minimum of six x is -1" ? Is it the same for Cos too?