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Edexcel A2 C3 Mathematics 12th June 2015

https://07a69ccf283966549a9350d1a66951a7bc96e2dc.googledrive.com/host/0B1ZiqBksUHNYZ0JQM1NRcmdHdXM/January%202010%20QP%20-%20C3%20Edexcel.pdf

why is 2x= 90, 270?

for question 8 for 1 solution

tanx graph cuts at 180,0 and 360?

Reply 2121

Sants

Original post by Freddy-Francis

But wastes time looking back :P

Do u really need to check :colondollar:

Nah im just saying cos if people forgot the rule in the exam due to pressure then they know they can look in the formula booklet

Reply 2122

Freddy-Francis

9

Original post by Sants

Nah im just saying cos if people forgot the rule in the exam due to pressure then they know they can look in the formula booklet

oh ok :2euk48l:

Reply 2123

Medboy100

2

Original post by studentwiz

what do you have to say for the sign change iteration proof question to get full marks

There is a sign change and f (x) is continuous therefore there is a root in the interval [a, b]

But usually sign change alone should suffice

Reply 2124

Freddy-Francis

9

I just did the hardest gold paper. It was way easier than the June 2014 R paper :frown:

Reply 2125

mechanism

5

Original post by Freddy-Francis

I just did the hardest gold paper. It was way easier than the June 2014 R paper :frown:

I know right! That's because the June 2014 R paper was all round disgusting, whereas the gold papers are combined 'harder' questions from all years.

Reply 2126

Freddy-Francis

9

Original post by studentwiz

https://07a69ccf283966549a9350d1a66951a7bc96e2dc.googledrive.com/host/0B1ZiqBksUHNYZ0JQM1NRcmdHdXM/January%202010%20QP%20-%20C3%20Edexcel.pdf

why is 2x= 90, 270?

for question 8 for 1 solution

tanx graph cuts at 180,0 and 360?

i didnt get that :s-smilie:

I got x = 45 , 135
and x = 22.5, 112.5

(edited 8 years ago)

Reply 2127

Sants

Which one are the edexcel more likely to ask us to do?
Rcos(x+a)
Rcos(x-a)
Rsin(x+a)
Rsin(x-a)

Reply 2128

Freddy-Francis

9

Original post by Sants

Which one are the edexcel more likely to ask us to do?
Rcos(x+a)
Rcos(x-a)
Rsin(x+a)
Rsin(x-a)

doesnt matter does it ?

Reply 2129

tonyrico123

Original post by Sants

Which one are the edexcel more likely to ask us to do?
Rcos(x+a)
Rcos(x-a)
Rsin(x+a)
Rsin(x-a)

They usually ask the + ones

Reply 2130

username1162972

18

Original post by Sants

Which one are the edexcel more likely to ask us to do?
Rcos(x+a)
Rcos(x-a)
Rsin(x+a)
Rsin(x-a)

Any of them.
Also quickly learn which one is use ful inndifferent cases as if edexcel wanted to be really bad they could just ask you to put it into harmonic form without saying which type.

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Reply 2131

AenigmaFx

9

Original post by studentwiz

https://07a69ccf283966549a9350d1a66951a7bc96e2dc.googledrive.com/host/0B1ZiqBksUHNYZ0JQM1NRcmdHdXM/January%202010%20QP%20-%20C3%20Edexcel.pdf

why is 2x= 90, 270?

for question 8 for 1 solution

tanx graph cuts at 180,0 and 360?

When cot2x = 0

cos2x/sin2x = 0 (multiply by sin2x)

gives us cos2x = 0

Then you solve for the 2 solutions from there.

Reply 2132

studentwiz

3

Original post by Freddy-Francis

i didnt get that :s-smilie:

I got x = 45 , 135
and x = 22.5, 112.5

was that for cot2x=1 or cot2x=0 ?

Reply 2133

studentwiz

3

Original post by AenigmaFx

When cot2x = 0

cos2x/sin2x = 0 (multiply by sin2x)

gives us cos2x = 0

Then you solve for the 2 solutions from there.

oh forgot about that that thanks so much

Reply 2134

sorarosa1998

1

What do I do if with the Rcos(..) the tan comes out as minus?

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Reply 2135

Freddy-Francis

9

Original post by studentwiz

was that for cot2x=1 or cot2x=0 ?

yes

Cot(2x) = 0
1/Tan(2x) = 0
Cos(2x)/Sin(2x) = 0
so Cos(2x) = 0
2x =90 and i used cast diagram to get the other solution

Cot(2x) =1
1/tan(2x) =1
1= tan(2x)
so 2x =45

Reply 2136

Freddy-Francis

9

Original post by sorarosa1998

What do I do if with the Rcos(..) the tan comes out as minus?

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then u did something wrong :biggrin:

I hope edexcel wont do that

Reply 2137

Freddy-Francis

9

Original post by physicsmaths

Any of them.
Also quickly learn which one is use ful inndifferent cases as if edexcel wanted to be really bad they could just ask you to put it into harmonic form without saying which type.

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wat do u mean :redface:

Reply 2138

studentwiz

3

Original post by Freddy-Francis

yes

Cot(2x) = 0
1/Tan(2x) = 0
Cos(2x)/Sin(2x) = 0
so Cos(2x) = 0
2x =90 and i used cast diagram to get the other solution

Cot(2x) =1
1/tan(2x) =1
1= tan(2x)
so 2x =45

thank you, there was 4 answers for that question btw

Reply 2139

sorarosa1998

1

Like when I compare coefficients one answer is minus? Then it will be tan -x/y
Usually it's plus never came across a minus but askin jic

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Edexcel A2 C3 Mathematics 12th June 2015

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