What is reciprocals? I've found this words when I'm doing my Physics Lab in my university. I'm from malaysia and my English is not so good. :)

the reciprocal of 4 is 1/4.

the reciprocal of x is x^-1.

You could say its just inverting the numerator and denominator.

Depends on the context. The recipricol of co-ordinate space is momentum space. Under the operation of addition, -2 is the recipricol of 2.

Recipricol usually means that if we multiply a quantity by its recipricol, we get 1. This is a limited view, but will treat you well for now.

I don't know if it's the same than in french, but it's also used for laws and properties. The reciprocal for "if A then B" is "if B then A". For exemple :

if x and y are integers, (x = -y) -> (x^2 = y^2)
the reciprocal is false because it would be :
if x and y are integers, (x^2 = y^2) -> (x = -y)

In a way it's a kind of "Recipricol usually means that if we multiply a quantity by its recipricol, we get 1" (dixit ryans) for laws.

Originally posted by SG-N
If x and y are integers, (x^2 = y^2) -> (x = -y)
If
x^2 = y^2
Then
x = y || x = -y || -x = y
You cannot just reverse that one.

Andreas

Originally posted by SG-N
I don't know if it's the same than in french, but it's also used for laws and properties. The reciprocal for "if A then B" is "if B then A". For exemple :

if x and y are integers, (x = -y) -> (x^2 = y^2)
the reciprocal is false because it would be :
if x and y are integers, (x^2 = y^2) -> (x = -y)

In a way it's a kind of "Recipricol usually means that if we multiply a quantity by its recipricol, we get 1" (dixit ryans) for laws.

in english, that statement is called the converse, not the reciprocal.

Originally posted by Loco
If
x^2 = y^2
Then
x = y || x = -y || -x = y
You cannot just reverse that one.

Andreas

uhh.... yeah, the converse isn t necessarily true. maybe that s why he said it was false?

Originally posted by Loco
You cannot just reverse that one.
That's why I wrote : "the reciprocal is false because it would be..."
Originally posted by lethe
in english, that statement is called the converse, not the reciprocal.
Mea culpa, thanks for the lesson :)

Originally posted by lethe
uhh.... yeah, the converse isn t necessarily true. maybe that s why he said it was false?

Perhaps...

thanks all.. :)