Mathematics: Post your doubts here!

[PhoenixAsh12]

Is the answer (2x(pi +4) -160)/pi?

Can you please show me how you did it step wise if you have time
Thanks

 

[PhoenixAsh12]

If the question asked you to get it in this form, then my method is not suitable. You should use the formal method just like Most_UniQue did.

Thank you. How is the formal method done?

 

[Dug]

Thank you. How is the formal method done?

Taking 1/pi common, we get A = 1/pi [ (pi+4)x^2 -160x +1600]
dA/dx = 1/pi[ 2(pi+4) -160]

Wow!! This was less troublesome.

 

[Dug]

View attachment 8724


People please help i cant figure out how to solve the second part. the answer in marking scheme is 7pi/12 but some how i end up getting pi/12.. please help asap i have amy maths exam tomorrow. :'(
this question is from summer 09 qp1.

Try searching the previous pages. This was answered yesterday.

 

[Most_UniQue]

Can you please show me how you did it step wise if you have time
Thanks

Dug solved it sooner

 

[PhoenixAsh12]

Taking 1/pi common, we get A = 1/pi [ (pi+4)x^2 -160x +1600]
dA/dx = 1/pi[ 2(pi+4) -160]

Wow!! This was less troublesome.

Thank you so much!!!

 

[Hussnain]

http://www.xtremepapers.com/papers/...AS Level/Mathematics (9709)/9709_w05_qp_1.pdf
8(ii) domain?

 

[Mosamali]

hi,
how would you find the range of a function in this question
q3ii) http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s10_qp_13.pdf

 

[PhoenixAsh12]

Can someone please solve this???

Function g(x)= 4-3sinx 1/2pi<=x<=A
(i) State the largest value of A for which g has an inverse

Thanks!

 

[rash1233]

http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_qp_11.pdf
7ii
can someone please help? Thanks

 

[Most_UniQue]

Can someone please solve this???

Function g(x)= 4-3sinx 1/2pi<=x<=A
(i) State the largest value of A for which g has an inverse

Thanks!

You have to draw the graph of this function which was asked in the previous question . g has an inverse when the graph is 1:1 meaning that for every value of y there is only one value of x therefore A will be 3/2pi.

 

[Most_UniQue]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_11.pdf
7ii
can someone please help? Thanks

dy/dx< 1/3 = > (3/(1+2x)^2) < 1/3

X will have two values. x=1 and x=-2

If you draw the graph , at x>1 and x<-2 the gradient is decreasing...
Thats my method...

 

[PhoenixAsh12]

You have to draw the graph of this function which was asked in the previous question . g has an inverse when the graph is 1:1 meaning that for every value of y there is only one value of x therefore A will be 3/2pi.

Isn't there a way to do it without the graph?

 

[Most_UniQue]

Isn't there a way to do it without the graph?

As far as I know , theres no other way. Didnt you draw the graph which was asked in the previous question?

 

[PhoenixAsh12]

As far as I know , theres no other way. Didnt you draw the graph which was asked in the previous question?

Yeah I get it now, thank you!

 

[Most_UniQue]

Yeah I get it now, thank you!

My Pleasure

 

[allysaleemally]

How do you find the range of a function and the domain of the inverse of that function in the form of a(x+b)^2 + c
or in the form of a-bcosx??
could please expain how to find the range and what do the values a,b,c denote?????

Thanks a million.

 

[Afeef]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_11.pdf
7ii
can someone please help? Thanks

for this you need to put 1/3 instead of dy/dx so this equation will be

1/3 = 3/(1+2x)^2

so by doing cross multiply we will get

(1+2x)^2 = 9
then open the bracket using a^2 + 2ab +b^2 formula and then simplify it! , you will get 2 values of X

 

[Toby Dawson]

Does anyone know where I can find the grade thresholds for the OCT/NOV 2002 9709 maths papers?

 

[USMAN Sheikh]

NOW ITS ALL ENDS AND TOMORROW IS THE DAY (