Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2017-12-30 11:44:30
- Hannibal lecter
- Member
- Registered: 2016-02-11
- Posts: 392
what is the solution for f(x) = exp(-x) ?
Hi, is there a root for the f(x) = e^-x ???
is it close to 0.571143115080177? or that wrong there is no any root?
please help me
Wisdom is a tree which grows in the heart and fruits on the tongue
Offline
#2 2017-12-30 14:51:23
- Jai Ganesh
- Administrator
- Registered: 2005-06-28
- Posts: 48,398
Re: what is the solution for f(x) = exp(-x) ?
Hi,
Hope this graph helps:
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
Offline
#3 2017-12-31 05:10:30
Re: what is the solution for f(x) = exp(-x) ?
Hi, is there a root for the f(x) = e^-x ???
is it close to 0.571143115080177? or that wrong there is no any root?
please help me
Where did you get 0.571143115080177 from? Are you stating the problem correctly? Or is something else meant by the word 'root' here?
Offline
#4 2018-01-04 09:05:55
- Hannibal lecter
- Member
- Registered: 2016-02-11
- Posts: 392
Re: what is the solution for f(x) = exp(-x) ?
I tried a matlab code to solve it, but thanks for helping I know it's nor have a root now..
but what about exp(-x)=x?
Wisdom is a tree which grows in the heart and fruits on the tongue
Offline
#5 2018-01-04 23:00:18
- iamaditya
- Member
- From: Planet Mars
- Registered: 2016-11-15
- Posts: 821
Re: what is the solution for f(x) = exp(-x) ?
Where did you get 0.571143115080177 from?
See the graph which Ganesh posted. You will see that it converges down to X-axis and almost touches it at that value.
Practice makes a man perfect.
There is no substitute to hard work
All of us do not have equal talents but everybody has equal oppurtunities to build their talents.-APJ Abdul Kalam
Offline
#6 2018-01-05 01:42:19
- Bob
- Administrator
- Registered: 2010-06-20
- Posts: 10,621
Re: what is the solution for f(x) = exp(-x) ?
See here:
http://www.mathsisfun.com/data/function … nc1=e^(-x)
Just add y = x as the second function and you'll see it does have that value as the solution.
Bob
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob 
Offline
#7 2018-01-06 01:24:06
Re: what is the solution for f(x) = exp(-x) ?
See the graph which Ganesh posted. You will see that it converges down to X-axis and almost touches it at that value.
No, it doesn't ever touch the x-axis. The exponential function is strictly positive: it can't have any roots.
However, if we take , then there is indeed a root. In fact, if we allow complex solutions, there are infinitely many of them, and they are precisely the nth values of the Lambert-W function, . This sequence generates all the complex roots.There is one real root, the so-called Omega constant, . There are several exact forms for the Omega constant, such as the 'power tower':and a nice integral relation is:
Offline
Pages: 1