taking log base e on both sides
logx + log(e^x)=log1
logx+x=0
-x=logx
taking antilog
x=-e^x
x+e^x=0
solve it via newton's raphson's law
x=-0.56714329
logx + log(e^x)=log1
logx+x=0
-x=logx
taking antilog
x=-e^x
x+e^x=0
solve it via newton's raphson's law
x=-0.56714329
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Using the Lambert W-Function, the solution is just:
x = W(1).
Note that the natural logarithm function and the Lambert W-Function are very similar. The natural logarithm function is the inverse of e^x; the Lambert W-Function is the inverse of x*e^x.
Alternatively, you can approximate the solution to x*e^x = 1 via Newton's Method. There is no way to get an exact value for x using elementary functions (note that the Lambert W-Function is not elementary).
I hope this helps!
x = W(1).
Note that the natural logarithm function and the Lambert W-Function are very similar. The natural logarithm function is the inverse of e^x; the Lambert W-Function is the inverse of x*e^x.
Alternatively, you can approximate the solution to x*e^x = 1 via Newton's Method. There is no way to get an exact value for x using elementary functions (note that the Lambert W-Function is not elementary).
I hope this helps!
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Use Newton method of roots
If r is an approximation to f(r)=0, then a better approximation is given by r(better)=r- f(r)/f'(r)
y= x*e^x - 1
y' = x*e^x + e^x
let r=.5
Next r = .5 - (.5*e^.5 - 1)/(.5*e^.5 + e^.5) = .571
Plug .571 in above equation and get .56716
Ultimate solution is r=.56714329040978
If r is an approximation to f(r)=0, then a better approximation is given by r(better)=r- f(r)/f'(r)
y= x*e^x - 1
y' = x*e^x + e^x
let r=.5
Next r = .5 - (.5*e^.5 - 1)/(.5*e^.5 + e^.5) = .571
Plug .571 in above equation and get .56716
Ultimate solution is r=.56714329040978
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plot the curves e^x and 1/x to find the place of the root.
find the root of f(x)=1-xe^x by any calculator or software.
find the root of f(x)=1-xe^x by any calculator or software.
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Try to graph y= x e^x and y=1 and find the intersection point.
They intersect at x=0.5671
They intersect at x=0.5671
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0.567