Author Topic: C1 and C2 DOUBTS HERE!!!!!  (Read 88834 times)

Offline abuelzouz

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Re: C2 DOUBTS HERE!!!!!
« Reply #30 on: May 07, 2010, 09:55:31 am »
i still dont get the trapezium rule!

Offline T.Q

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Re: C2 DOUBTS HERE!!!!!
« Reply #31 on: May 07, 2010, 10:17:31 am »
could u just type the equations for me
am rili sorry :)

srry , u dont solve simultaneously

the solution is attached 
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Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #32 on: May 07, 2010, 11:18:09 am »
srry , u dont solve simultaneously

the solution is attached 

got it !! thx alot!! ;D ;D ;D ;D
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Offline T.Q

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Re: C2 DOUBTS HERE!!!!!
« Reply #33 on: May 07, 2010, 12:51:58 pm »
got it !! thx alot!! ;D ;D ;D ;D

u r  welcome

in my drawing i made some mistakes b=5 , a=4
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Offline abuelzouz

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Re: C2 DOUBTS HERE!!!!!
« Reply #34 on: May 07, 2010, 01:47:14 pm »
i still dont get the trapezium rule!

!! ??

Offline T.Q

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Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #36 on: May 07, 2010, 03:36:58 pm »
The curve C has equation y = cos( x + pie/4) ,  0 < x < 2pie.

 

(a)   Sketch C.                                                                                                                   (2 marks)

 

(b)   Write down the exact coordinates of the points at which C meets the coordinate axes.

       (3 marks)

 

(c)   Solve, for x in the interval 0 <x < 2pie,

cos ( x + pie/4) = 0.5,
            giving your answers in terms of p.



plzzz plzz could anyone solve this...im having a brain breakdown god dammiiitttttt
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: C2 DOUBTS HERE!!!!!
« Reply #37 on: May 07, 2010, 03:40:07 pm »
Please send the exact question paper.
« Last Edit: May 07, 2010, 03:56:23 pm by The Mysterious Dude »

Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #38 on: May 07, 2010, 03:53:00 pm »
Q7
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: C2 DOUBTS HERE!!!!!
« Reply #39 on: May 07, 2010, 04:07:29 pm »
Ok, I answered question 1. Just in degrees. It is simple the cos(x) graph moved 45 degrees back.

(b) You know the x-axis intercepts. They are \frac{\pi}{4} and \frac{5\pi}{4}. They are simple the places where the original cos(x) crosses the x-axis but -\frac{\pi}{4} those values.

(c) cos(x+\frac{\pi}{4})=0.5

There are two possible values of cos(x)=0.5

Now you also are told to find all intercepts, so also y axis. Simple make x=0 and calculate the value of y through the equation to get 0,\frac{1}{\sqrt{2}}

They are:

\frac{\pi}{3} and \frac{5\pi}{4}. So you simply now equate this back into the equation.

And you will get \frac{\pi}{12} and \frac{17\pi}{12}.

Hope that helps.
« Last Edit: May 07, 2010, 04:14:54 pm by The Mysterious Dude »

Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #40 on: May 07, 2010, 04:35:06 pm »
Ok, I answered question 1. Just in degrees. It is simple the cos(x) graph moved 45 degrees back.

(b) You know the x-axis intercepts. They are \frac{\pi}{4} and \frac{5\pi}{4}. They are simple the places where the original cos(x) crosses the x-axis but -\frac{\pi}{4} those values.

(c) cos(x+\frac{\pi}{4})=0.5

There are two possible values of cos(x)=0.5

Now you also are told to find all intercepts, so also y axis. Simple make x=0 and calculate the value of y through the equation to get 0,\frac{1}{\sqrt{2}}

They are:

\frac{\pi}{3} and \frac{5\pi}{4}. So you simply now equate this back into the equation.

And you will get \frac{\pi}{12} and \frac{17\pi}{12}.

Hope that helps.

am rili sorry i got everything except part c
i mean first of all im equating x=0 in the equation but the answer is 0.9999.....
 and where did u get the pie/3 from?
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: C2 DOUBTS HERE!!!!!
« Reply #41 on: May 07, 2010, 06:10:10 pm »
am rili sorry i got everything except part c
i mean first of all im equating x=0 in the equation but the answer is 0.9999.....
 and where did u get the pie/3 from?

No, X does not equal 0. You have to find out the two values of cos(x)=\frac{1}{2}

Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #42 on: May 07, 2010, 06:20:49 pm »
No, X does not equal 0. You have to find out the two values of cos(x)=\frac{1}{2}

ok i found them as pie/3 and 5pie/3 ??
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Offline Saladin

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Re: C2 DOUBTS HERE!!!!!
« Reply #43 on: May 07, 2010, 06:29:21 pm »
Here u go.

x+\frac{\pi}{4}=\frac{\pi}{3}


x=\frac{\pi}{12}


x+\frac{\pi}{4}=\frac{5\pi}{3}


x=\frac{17\pi}{12}

Offline halosh92

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Re: C2 DOUBTS HERE!!!!!
« Reply #44 on: May 07, 2010, 06:38:29 pm »
Here u go.

x+\frac{\pi}{4}=\frac{\pi}{3}


x=\frac{\pi}{12}


x+\frac{\pi}{4}=\frac{5\pi}{3}


x=\frac{17\pi}{12}


thankyou soooooooo muchhhhhhhhhhh
ure a life savor and sorry for the trouble  :-[
everyday we wake up is a miracle, then how do we say miracles dont happen?????