# Mathematics: Post your doubts here!

Discussion in 'International A And AS Level' started by XPFMember, Sep 8, 2011.

1. ### Unknown202

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so cuz the triangle is isoscles both angle are equal k thx alot

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3. ### Wâlèé Atèéq

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Can anyone help me? I'm in A2 and it's just 4 months left my subjects are Phy, Maths and C.S. Any hope ?

4. ### A*****

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Post the complete question

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5. ### Ebrahim12

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(i)
It being a one mark question is a hint at a clever solution:

(ii)
From main diagram:
AreaTotal = 2*AreaB + AreaCircle (or 2*AreaSemiCircle)

AreaA = (i) - AreaB

Last edited: Jan 4, 2019
6. ### Ebrahim12

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Was your answer to the first part y = 70e^[e^(-3t) - 1] ?

As t goes to infinity,
e^-3t tends to zero​
thus,
y tends to 70e^[0 - 1] = 70e^-1​

so we have:
yFinal = 70e^-1
yStart = 70 (from main question)

p = (yFinal/yStart)*100
p = 100e^-1​

Last edited: Jan 4, 2019
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7. ### EXPERTS

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help required !!!!!!! in part b

Last edited: Jan 6, 2019
8. ### A*****

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9. ### A*****

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Thanx alot!!

10. ### A*****

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How are the values of α and β calculated in the last part? Anyone plz help.....

11. ### A*****

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For b (i), AC is the diameter of the circle so APC will be the angle opposite to the diameter, i.e. angle in a semicircle=90°
Or you can think of it by the other rule...ABCP is a quadrilateral with its vertices touching the circumference so opposite angles will be equal. Hence, angle APC=angle ABC

In b (ii), angle APB is subtended by the chord AB, whereas angle BPC by the chord BC.Angles subtended by chords of equal length are equal and since AB=BC, the stated angles are equal.

In b (iii) (a) APC=90 and APB and BPC are equal, so APB=90/2=45
In b(iii) (b), angle CPD is also subtended by an equal chord so it will also equal angle APB i.e. 45. Hence, APD= 45+45+45=135

For b(iv) see the diagram

So angle PDC=90+8=98

12. ### Ebrahim12

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What are the answers? Is alpha = 1.23?

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13. ### A*****

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That's 0.424

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14. ### Ebrahim12

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This makes sense?

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15. ### Lemniscates

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Depends on how well are you doing right now. You can inbox me for discussing about this topic.

16. ### Lemniscates

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17. ### EXPERTS

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need help in part b and c

18. ### Ebrahim12

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b)
Having two sides be the same makes it an isosceles triangle
360 = 66 + 2x
C)
ADE and EFC are equal (alternate angles)
FEC and AED are equal

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19. ### A*****

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Better to post in O level thread

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20. ### EXPERTS

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dont be angry sis

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