Saying:
If a=1, then 1≠b
is logical, whereas saying:
If a=1, then 1=b
is illogical or at least requires more explanation than the first.
That is the logic I'm trying to convey.
No, no, no, please, Chriliman. Look back at what you wrote earlier.
"Always assume there is someone who knows more than you do and that you can learn something from them."
"a" and "b" are just two seperate variables. Two seperate expressions that can be filled with values, or assigned to seperate attributes. They do not depend on each other.
So simply saying "if a = 1, then b ≠ 1" is not "logical". Just as simply saying "if a = 1, then b = 1" is not "logical". There is not yet any relation established between a and b.
Such a relation needs to be established, either by definition or by calculation.
For example:
Let a be the number of dollar bills in your wallet. Let b be the price of bread in dollars. c will be the number of loafs of bread you can buy.
c=a/b
Now to fill it with values. Assume you have ten dollars, and the price of bread is two dollars per loaf.
a=10, b=2
c=a/b
c=10/2
c=5
You can buy five loafs of bread.
Or you have one dollar, and the price of bread is one dollar per loaf.
a=1, b=1
c=a/b
c=1/1
c=1
Just one bread now. See, different variables...
same value. In this case, even
three variables with the same value! Got it?
Another example:
The famous "Pythagorean theorem": in any triangle with one right angle (90°), the square of the side opposite the right angle (the hypotenuse, called "c") is equal to the sum of the squares of the other two sides (the catheti, called "a" and "b").
You certainly have heard it or read it somewhere... "a squared plus b squared is c squared"
Example: Right angled triangle, the cathetus a = 3, the cathetus b = 4. What is the length of the hypotenuse?
c^2 = a^2 + b^2
c = sqr (a^2 + b^2)
In this case: c = sqr(3*3 + 4*4)
c = sqr(9+16)
c = sqr(25)
c = 5
Example: Right angled triangle, cathetus a = 1, hypothenuse c = sqr(2). What is the length of the other cathetus b?
Again: c^2 = a^2 + b^2
Thus: b^2 = c^2 - a^2
b = sqr(c^2 - a^2)
In this case: b = sqr( sqr(2)*sqr(2) - 1*1)
b = sqr(2 - 1)
b = sqr(1)
b = 1.... equal to what a is.
Different variables, denoting different attributes...
same value.
It's not rocket science, or brain surgery. Just simple algebra.