Mathematics: Post your doubts here!

[rexsun]

Emergent, please help!

I have no doubt in solving this problem as I have nearly finished the further. Yet I need to make sure I score all the method mark given. for ii), please take a look at the mark scheme as below.

Can anybody tell how to use the correct trig formulae to obtain a 3-term quadratic in tan sita, sin 2sita,cos 2sita, or tan2sita?

Very very time-limited, please reply quickly, thanks!!!!

 

[RoOkaYya G]

I got Q3 and most of Q4, thanks alot! <3
In question 4 tho, how did you get the area of AOB? Where did r^2 come from?

using formula 0.5 * ab * sin c
use the radius r as the side of the triangle. it is isoceles.

 

[RoOkaYya G]

Emergent, please help!
View attachment 47796
I have no doubt in solving this problem as I have nearly finished the further. Yet I need to make sure I score all the method mark given. for ii), please take a look at the mark scheme as below.
View attachment 47797
Can anybody tell how to use the correct trig formulae to obtain a 3-term quadratic in tan sita, sin 2sita,cos 2sita, or tan2sita?

Very very time-limited, please reply quickly, thanks!!!!

use double angle formulas
btw its written "hence" so it means u shld use the answer from part (i) in part (ii) to some extent.

 

[Thought blocker]

RoOkaYya G <3 Thanks.

 

[Thought blocker]

Actually, yes, but they are from the recent 2014 May June Paper.
http://justpastpapers.com/wp-content/uploads/2014/05/IMG_3474.jpg
(The papers aren't exactly out yet, so this is a best version I could find^)

Question 3 and 4 (i) part.
For Q3, I didn't get the reflex part at all. I just know how to do it with acute, obtuse and right angle. If you can help me with the concept, I will so grateful!

WORKED SOLUTION :¬
http://justpastpapers.com/9709_s14_ms_12/

 

[Thought blocker]

Thanks alott! :')
I got a silly question, but, when we are applying square root to both sides in question 9, why is only K + and - ? Why not + and - (x+2) too?

Here, we have to go step by step.
You will come at, k squared = (x + 2) squared. So you will first remove square from k or (x + 2) your choice, for ex, lets take k for now, so, k = Root of [(x + 2) squared] hence it remains (x+ 2) Square gets off due to root. And after you remove root, there is +/- sign coz we dk either that term is + or -
Same way if you take root on k it will be +/-(x + 2) = k
Solving this you will end with the same solution,
x + 2 = k, x = k - 2 --> (1)
-x - 2 = k, x = -k - 2 --> (2)

Hope so you get it.

 

[Emma23]

Whole 6?

sorry, 6(ii) .

 

[Thought blocker]

sorry, 6(ii) .

6 ii)
you first plot points A and B on the diagram and i am assuming you know how to do that
next you find the mid point between A and B
you get -1/2-1/2i
this will be the centre of the circle
no you have to find the radius of the circle
find the distance between the two points using sqrt[(x2-x1)^2+(y2-y1)^2 and you get an answer
square root of answer will give you the radius

 

[Emma23]

6 ii)
you first plot points A and B on the diagram and i am assuming you know how to do that
next you find the mid point between A and B
you get -1/2-1/2i
this will be the centre of the circle
no you have to find the radius of the circle
find the distance between the two points using sqrt[(x2-x1)^2+(y2-y1)^2 and you get an answer
square root of answer will give you the radius

Thank you so much I understood it.

 

[Daniel Lim]

To all those who are taking A Level,

Here are the full tips on how to score every subject in AS and A2, which includes the tips on studying and the answering techniques.

http://daniellimjj.blogspot.com/2014/09/complete-tips-for-cie-as-and-level.html

 

[Rutzaba]

Here, we have to go step by step.
You will come at, k squared = (x + 2) squared. So you will first remove square from k or (x + 2) your choice, for ex, lets take k for now, so, k = Root of [(x + 2) squared] hence it remains (x+ 2) Square gets off due to root. And after you remove root, there is +/- sign coz we dk either that term is + or -
Same way if you take root on k it will be +/-(x + 2) = k
Solving this you will end with the same solution,
x + 2 = k, x = k - 2 --> (1)
-x - 2 = k, x = -k - 2 --> (2)

Hope so you get it.

helping others i see..... glad to have left a tradition

 

[Thought blocker]

helping others i see..... glad to have left a tradition

Wanna join?

 

[Rutzaba]

Nopes studies hard already

 

[Thought blocker]

Nopes studies hard already

Hows university studies going?

 

[rexsun]

use double angle formulas
btw its written "hence" so it means u shld use the answer from part (i) in part (ii) to some extent.

Could you explain it in more detail please.. I think it would not be a good idea to use the double angle formula, because you can't cancel the constant 2 on the RHS. Please write down full detail, thanks!!

 

[Thought blocker]

Could you explain it in more detail please.. I think it would not be a good idea to use the double angle formula, because you can't cancel the constant 2 on the RHS. Please write down full detail, thanks!!

Which question?
Where is link?
Which paper?

 

[RoOkaYya G]

Could you explain it in more detail please.. I think it would not be a good idea to use the double angle formula, because you can't cancel the constant 2 on the RHS. Please write down full detail, thanks!!

i dint try it but thts how basically we do it, right?
Thought blocker please see to it. im not good enough to work this out :/

 

[Thought blocker]

i dint try it but thts how basically we do it, right?
Thought blocker please see to it. im not good enough to work this out :/

Which question?
Where is link?
Which paper?

 

[RoOkaYya G]

Emergent, please help!
View attachment 47796
I have no doubt in solving this problem as I have nearly finished the further. Yet I need to make sure I score all the method mark given. for ii), please take a look at the mark scheme as below.
View attachment 47797
Can anybody tell how to use the correct trig formulae to obtain a 3-term quadratic in tan sita, sin 2sita,cos 2sita, or tan2sita?

Very very time-limited, please reply quickly, thanks!!!!

Thought blocker this one!!

 

[Thought blocker]

Thought blocker this one!!

Where is the question?