Today, while I was browsing the web I encountered this piece of math:
a = b
a + a = a + b
2a = a + b
2a - 2b = a + b - 2b
2(a - b) = a + b - 2b
2(a - b) = a - b
2 = 1
On first sight you might think it is correct, but if you look a little bit closer you can easily see the error!
let’s try it again:
a = b //true
a + a = a + b //true
2a = a + b //true
2a - 2b = a + b - 2b //true
2(a - b) = a + b - 2b //true
2(a - b) = a - b //true <=> 2a - 2b = a - b <=> a - b = a - b <=> 0 = 0
2 = 1 //false (should be 0 = 0)
that’s it for my ranting =)
You failed.
In math by default they take for a var 1.
The error isn’t there, it’s on the second line.
“a + a = a + b //true”
They duplicated these vars, why? I don’t know, but there it is.
I would say the whole example is just crap.