Author Topic: C1 and C2 DOUBTS HERE!!!!!  (Read 85852 times)

Offline SZM

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #675 on: February 27, 2012, 03:06:01 pm »
q3 for SZM
For q4 I really need a diagram. In the question it says there is one.

Sir question no. 4), the diagram that u have drawn is little correct. I wil give u an extra information about diagram. The diagram says that there 6 rectangular boxes in a row side from left to the right and there are 2 rectangular boxes in column sides from top to bottom. The variable that u have labelled is correct. I have seen ur diagram under question no 3.) where u have scribbled.

Hope this information wil make u understand.... Pls let me know if u dont understand the information//

Thanx for solving the question no 3.) . May God Bless u.

Question no 9.), I have corrected this question again,

The part of the curve with equation y= 3 + 5x + xsquare - xcube. The curve touches the x-axis at A and crosses the x-axis at C. The points A and B are stationary points on the curve.
 a. ) Show that C has coordinates (3, 0)
 b. ) Using calculus and showing all your working, find the coordinates of A and B.

hope I have replied with what u have asked me for..

Waitn 4 ur reply.

Offline astarmathsandphysics

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #676 on: February 27, 2012, 03:16:03 pm »
q9 attached

Offline YU-GI-OH!

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #677 on: April 27, 2012, 06:29:35 pm »
May someone please solve question 5b of the June 2011 C2 paper for me.
Thanks in advance :)

Offline xainer

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #678 on: August 25, 2012, 11:51:16 am »
Hi! I am doing C1 and I am having a tough time with this question. Can't get the answer for the last part.
Each year, for 30 years, David will pay money into a savings scheme. In the first year he pays 800 pounds. His payments then increase by 60 pounds each year, so that he pays 860, 920 in the third year and so on.
a) Find how much David will pay in the 30th year.
b) Find the total amount that David will pay in over the 30 years.
c) David will retire when his savings reach 65000. Find out how much longer he will have to work.
Can u tell the answer for the last part? it's where i'm stuck. Because of so big numbers, it's difficult to solve the quadratic equation which i'm getting. tried reducing it also.

Offline Saladin

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #679 on: August 25, 2012, 03:13:04 pm »
@xanier:

(a) Common difference = 60
     Therefore, value on 30th year = 60(30) + 740
(b) (n/2)(2a + (n-1)d)
     = (30/2)(2(800) + (29)60)
     = 50100
(c) You just use the equation in (b) and equate it to 6500, and solve for n. You get something like 35.45..so 36...
     Also, if the person does not increase his amount after the 30th year, it will still take 36 years.
     Read the question again, maybe that will help you out.

Offline Saladin

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #680 on: August 25, 2012, 03:14:14 pm »
May someone please solve question 5b of the June 2011 C2 paper for me.
Thanks in advance :)

Don't have the paper on me. Next time, please attach the paper.

Offline xainer

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #681 on: August 25, 2012, 03:53:01 pm »
@xanier:

(a) Common difference = 60
     Therefore, value on 30th year = 60(30) + 740
(b) (n/2)(2a + (n-1)d)
     = (30/2)(2(800) + (29)60)
     = 50100
(c) You just use the equation in (b) and equate it to 6500, and solve for n. You get something like 35.45..so 36...
     Also, if the person does not increase his amount after the 30th year, it will still take 36 years.
     Read the question again, maybe that will help you out.

okay. will try. thanks for the quick reply! :)

Offline xainer

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #682 on: August 25, 2012, 04:44:14 pm »
@xanier:

(a) Common difference = 60
     Therefore, value on 30th year = 60(30) + 740
(b) (n/2)(2a + (n-1)d)
     = (30/2)(2(800) + (29)60)
     = 50100
(c) You just use the equation in (b) and equate it to 6500, and solve for n. You get something like 35.45..so 36...
     Also, if the person does not increase his amount after the 30th year, it will still take 36 years.
     Read the question again, maybe that will help you out.

can u tell hw to do that qustn without using calculator? the numbers are very big n using the quadratic formula doesn't give a whole number inside the square root. i checked using calculator...

Offline xainer

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #683 on: August 27, 2012, 04:04:24 pm »
Can anyone please give a link or document which explains about differentiation? especially the introductory part?

Offline astarmathsandphysics

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Offline astarmathsandphysics

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Re: C1 and C2 DOUBTS HERE!!!!!
« Reply #686 on: January 24, 2013, 11:22:16 am »
Got this question from someone. Answer in attachment.

1)
Prove that   sin2x /(1+cos2x) = tanx


2)
Solve the eqn  2sec2X + tanX - 3 = 0             (X stands for theeta and  0<=X<=180)