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## #1 2009-03-10 03:53:14

ganesh
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Registered: 2005-06-28
Posts: 23,044

### Question Bank : Age Group 14-15 : XI

1. Find the equation of the straight line joining the point of intersection of 3x - y + 9 = 0 and
2y + x - 4 = 0 to the point of intersection of 2x + y = 4 and 2y = x + 3.

2. The vertices of a triangle ABC are A (-3, 3), B (-1, -4), and C (5, -2). M and N are the midpoints of AB and AC. Show that MN is parallel to BC and

.

3. Find the equation of the line parallel to the Y axis and passing through the point of intersection of 3x - 4y - 9 = 0 and x - 4y - 2 = 0.

4. Find the orthocenter of the triangle whose vertices are (-2, 1), (-1, -4), and (0, -5).

5. Prove that the line segments joining the mid points of the adjacent sides of a rhombus form a rectangle.

6. ABCD is a trapezium with AB || CD. The diagonals AC and BD intersect at E. If
Δ AED ||| Δ BEC, prove that AD = BC.

7. Two circles intersect each other internally at P. If ACP and BDP are the lines meeting the two circles at A, B and C, D respectively, prove that

.

8. Show that

.

9. If A = 30°, and B = 60°, verify that
(i) sin(A + B) = sin A cos B + cos A sin B
(ii) cos(A + B) = cos A cos B - sinA sin B.

10. From the top of a building 60 meters high, the angle of depression of the top and bottom of a tower are observed to be 30° and 60° respectively. Find the height of the tower.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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## #2 2013-03-24 07:21:58

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Question Bank : Age Group 14-15 : XI

Hi;

4) The orthocenter is located at (-10,-7).

Last edited by bobbym (2013-03-24 08:00:48)

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #3 2013-03-25 05:45:30

Agnishom
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From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,769
Website

### Re: Question Bank : Age Group 14-15 : XI

What is the meaning of |||?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

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## #4 2013-03-25 05:53:17

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Question Bank : Age Group 14-15 : XI

Maybe it is supposed to be a sign for congruence?

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #5 2013-03-25 05:58:15

Agnishom
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From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,769
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### Re: Question Bank : Age Group 14-15 : XI

Then question 6 would be not a question at all.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

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## #6 2013-04-04 20:49:06

hammana
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Registered: 2012-03-02
Posts: 48

### Re: Question Bank : Age Group 14-15 : XI

Hi Agnishom

Question 6 means probably that triangles AED and BEC are similar . We have to proof that:

EB/EA=EC/ED -->EB*ED=EA*EC --> A,B,C,D are concyclic --> AD=BC

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## #7 2013-04-04 23:56:52

Agnishom
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From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,769
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### Re: Question Bank : Age Group 14-15 : XI

1. How does that make them concyclic?
2. How can you say that the opposite sides of a concyclic quadrilateral are equal?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

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