Thread: Set Prove or Disprove

Last help i need for today

Prove or Disprove:

(A multiply C) Union (B multiply D) = (A Intersection B) multiply (C Intersection D).

Please help...

When multiply is coming in SET, my brain is not working

Did you mean: ?

If so, then you should note that:

for any two sets . Once this is clear, this should be easy to solve!

Originally Posted by faisalnet5

Prove or Disprove:
(A multiply C) Union (B multiply D) = (A Intersection B) multiply (C Intersection D).

You are asked Prove or Disprove:

First, is read "A cross C"; not (A multiply C)
It is the cross product of set A with set C.
.

Now if is it true?

Thanks a lot Plato...u know i am new in this room and yet don't know how to use the signs like u did. Will be on the road soon

By the way, so if someone ask me to prove :

\left( {A \times C} \right) \cup \left( {B \times D} \right) = \left( {A \cap B} \right) \times \left( {C \cap D} \right)

Do i have to take some arbitrary sets like that A={1,2}, C={2,3}...and solve it or by using set notation also we can prove or disprove?

Regards

Originally Posted by faisalnet5

Thanks a lot Plato...u know i am new in this room and yet don't know how to use the signs like u did. Will be on the road soon

By the way, so if someone ask me to prove :

\left( {A \times C} \right) \cup \left( {B \times D} \right) = \left( {A \cap B} \right) \times \left( {C \cap D} \right)

Do i have to take some arbitrary sets like that A={1,2}, C={2,3}...and solve it or by using set notation also we can prove or disprove?

Regards

not exactly. Often we use algebraic method or deduction,
like or "if A is in B, then ...."..
But this is used to prove something. If you want to disprove, just give a conterexample.