Mathematics - 4 September 2006

Prove: If A, B, C are sets, then (A-B) X C = (AXC) - (BXC), where "A-B" is the set containing all elements of A that are not in B, and AXC denotes the Cartesian product between A and C. Obviously, to prove this, one must show that for any ordered pair (x,y), if it is contained in the set on the left side of the equation, it is necessarily in the one on the right, and vice versa. The proof seems almost obvious. I just want someone to write down a set of logical steps showing how they arrive at the above statement.

2006-09-04 05:34:39 · 1 answers · asked by Anonymous

A train is crossing two bridges of 430m and 550m in 30sec and 36 sec respectively. find the speed of the train ?

2006-09-04 05:22:33 · 8 answers · asked by madan raj 1

Imagine you are on a game show and the idea is to win a car. There are 3 doors and behind 2 of them, there is a goat and behind the last 1- the car.
You choose a door. The host (Who knows what is behind the doors) opens a different door with a goat behind.
Now there are 2 doors left and you have 2 options:

1. Stick with your door

2. Swap doors

Should you stick, swap or does it not matter? (10 points for the correct answer and best reason) have fun! :-)

2006-09-04 05:14:23 · 15 answers · asked by Anonymous

For the equation x+ /2x-1/ = 3 , the answers are -2 and 4/3.
But there is no solution for the equation 3 + /2x-1/ = x.
WHY?

2006-09-04 04:58:43 · 5 answers · asked by Anonymous

Can anyone capture the following logic in a nested-IF statement so I can copy/paste straight into Excel?

£0.01 - £4.99 10% for the amount of the selling price up to £4.99
£5.00 - £9.99 10% of the initial £4.99 plus 8% of the remaining selling price balance
£10.00 - £49.99 10% of the initial £4.99 plus 8% of the initial £5.00 - £9.99 plus 6% of the remaining selling price balance
£50.00 - £499.99 10% of the initial £4.99 plus 8% of the initial £5.00 - £9.99 plus 6% of the initial £10.00 - £49.99 plus 4% of the remaining selling price balance
Over £500 10% of the initial £4.99 plus 8% of the initial £5.00 - £9.99 plus 6% of the initial £10.00 - £49.99 plus 4% of the initial £50.00 - £499.99 plus 2% of the remaining closing value balance

2006-09-04 04:31:03 · 6 answers · asked by Anonymous

Given f(x)=2x and g(x)=4x-3

show that f^-1(g^-1(x))=g(f(x))^-1

this involves composite functions

2006-09-04 04:20:52 · 8 answers · asked by Yahoo! 1

make this fast.izzat ka sawal hai

2006-09-04 04:09:54 · 8 answers · asked by TONY 2

How can I prove the cordinality of the sets of even, odd, and natural numbers are equal?

Thanks in advance!

2006-09-04 03:13:59 · 3 answers · asked by ? 3

how do you prove that in a triangle, the greater angle has the greater side opposite to it? i know how to prove that the greater side has the greater angle opposite to it, but can someone please tell me the converse of this theorum?

2006-09-04 02:18:33 · 7 answers · asked by Smithereenian 2

I want to know what others think?? Should i just leave it as it is or should I do the test again and try to get an A or B???

Doing the test again= Time+money

I dont know if i can get into 6 form with this grade for maths....

2006-09-04 02:05:12 · 10 answers · asked by Anonymous

2006-09-04 01:50:46 · 16 answers · asked by Anonymous

Start:
-8 = -8
4 - 12 = 16 - 24
4 - (6 + 6) = 16 - (12 + 12)
4 - (6 + 6) + 9 = 16 - (12 + 12) + 9
factor:
(2 - 3)² = (4 - 3)²
2 - 3 = 4 - 3
2 = 4
divide by 2
1 = 2
Add 1:
1 + 1 = 3

What's wrong with this proof?
Also does a^1/2 = b^1/2 imply a=b ?

2006-09-04 01:17:21 · 11 answers · asked by English Learner 2

2006-09-04 00:59:32 · 5 answers · asked by Edson F 1

explain this pattern CLEARLY and provide the next one in the sequence...

1
11
211
12211
11222211

2006-09-04 00:54:49 · 6 answers · asked by sheldyshawiwongka 2

2006-09-04 00:16:20 · 10 answers · asked by Uthman A 5

2006-09-04 00:13:35 · 17 answers · asked by missioncat_2007 1