Originally posted by THUDandBLUNDER If you differentiate e^x wiith respect to x it remains unaffected.
That is, letting y = e^x, dy/dx = e^x
But d(e^x)/dy = dy/dy = 1
e^x has been changed into a constant.

Differentiation, integration and exponentials etc are what put me off mathematics forever. Until then I had a reasonably good concept and feel for the subject. But at this point I stopped being able to build a mental picture of what it was about. I must be a thick c888 or something.
Anyways, I shall tell it to my brother. He has a PhD in Mathematics. That will be the true acid test as to whether it is funny or not. ðŸ˜›

Originally posted by jimslyp69 Differentiation, integration and exponentials etc are what put me off mathematics forever. Until then I had a reasonably good concept and feel for the subject. But at this point I stopped being able to build a mental picture of what it was about. I must be a thick c888 or something.
Anyways, I shall tell it to my brother. He has a PhD in Mathematics. That will be the true acid test as to whether it is funny or not. ðŸ˜›

Don't worry. One only really needs algebra anyway. And that can be largely intuitive, if that's the right word.

Originally posted by Bowmann Don't worry. One only really needs algebra anyway. And that can be largely intuitive, if that's the right word.

Cheers for the words of encouragement but I suppose that all depends on what you want to do with it. Just lucky I don't want to be a programmer really. ðŸ˜²

Originally posted by jimslyp69 Cheers for the words of encouragement but I suppose that all depends on what you want to do with it. Just lucky I don't want to be a programmer really. ðŸ˜²

Originally posted by Bowmann I managed to write programs using O-level maths.

I got an A in GCSE maths but I wouldn't say i was anywhere near O level standard. My Brother had an O level maths exercise book from 1969, that he acqured from my Grand Ma. He had serious difficulties solving the problems in it whilst he was at A level standard in 1990.

Originally posted by THUDandBLUNDER But his original post didn't even contain a question mark.
So he must be kindly telling us that a person called Ever heard of the Fibonacci sequence, right? ðŸ˜µ

Therefore, in order to give this thread a raison d'etre, here is a joke:

e^x is walking down the road one day when he meets several other functions coming the other way. One of them ...[text shortened]... Hi, I'm e^x"

"Hello," replied the differential, grinning broadly, "I'm d/dy"

d/dy could not split e^x.
e^x is a real tough guy.
To d/dy's dismay, all it can do is put e^x under the table---to try to humiliate e^x.
e^x just keeps laughing down there.

y = e^x

d/dx y = d/dx e^x
dy/dx = e^x ------nothing doing.

d/dy y = d/dy e^x
dy/dy = e^x dx/dy
1 = e^x dx/dy
dx/dy = 1 / e^x -----underneath, but still intact.

Originally posted by phgao d/dy could not split e^x.
e^x is a real tough guy.
To d/dy's dismay, all it can do is put e^x under the table---to try to humiliate e^x.
e^x just keeps laughing down there.

y = e^x

d/dx y = d/dx e^x
dy/dx = e^x ------nothing doing.

d/dy y = d/dy e^x
dy/dy = e^x dx/dy
1 = e^x dx/dy
dx/dy = 1 / e^x -----underneath, but still intact.

Originally posted by phgao d/dy could not split e^x.
e^x is a real tough guy.
To d/dy's dismay, all it can do is put e^x under the table---to try to humiliate e^x.
e^x just keeps laughing down there.

y = e^x

d/dx y = d/dx e^x
dy/dx = e^x ------nothing doing.

d/dy y = d/dy e^x
dy/dy = e^x dx/dy
1 = e^x dx/dy
dx/dy = 1 / e^x -----underneath, but still intact.

y = e^x
dy/dx = e^x
dx/dy = e^-x
Fair enough.

But we re not differentiating x wrt y
We are differentiating e^x wrt y
Having done so, we get a constant (1)

I heard a really funny (to a maths geek) story about little Polly Nomial once, and how she lost her convergency. It's probably rolling around the internet somewhere if I can be bothered...

...ah yes, here's a version. It was funnier when read aloud with lots of meaningful pauses.

Originally posted by orfeo I heard a really funny (to a maths geek) story about little Polly Nomial once, and how she lost her convergency. It's probably rolling around the internet somewhere if I can be bothered...

...ah yes, here's a version. It was funnier when read aloud with lots of meaningful pauses.

That's a fcuked up story. It's about a function being raped and getting pregnant, no? And the cautionary at the end is to keep your kids locked up forever. It was probably funnier in the 50's, although I will say the language was cleverly used.