1 ACCEPTED SOLUTION
Accepted Solutions
I agree with Werner. I find the easiest way to think about this is to take logs:
Alan
Valery Ochkov wrote:
Sorry, may be I do not understand some one, but where is the problem:
Thats the problem:
Those two values are demanded to be the same.
Valery Ochkov wrote:
Delete y:=0
?? In as much would this help to solve the equation given???
The equation has real solutions only for x < -2.3822943 (approx.), so the given range from 0 to 300 has to fail, even if you would do it right.
The two solutions (for valid values of x) look like this:
Look up the Lambert W function in the literature for further information.
Here is a sheet that should help and an animation demonstrating why values of x must be smaller than -2.383..
I still think that number should be -1-ln(4) and Mathcad allows for slightly bigger values only because of numerical inaccuracies in the solve block - anybody any comments on that?
A more detailled video (higher FRAME number) was uploaded here: http://communities.ptc.com/videos/4498
EDIT: Added 3D-plot
I haven't really grasped Lambert W function
You don't need to do.
The small solveblock does what you want
- get a set of y-values corresponding to x-values.
The problem is that you get two different y-values for any (valid) given x-value and so I provided the function Sol() to get both. Thats also the reason the table of values i provided has three columns - the first being the x-values and the next two the two different y's.
In the animation provided you could see why there are two solutions and that one of them approaches zero with lower values of y while the other grows.
I have no idea which of the two solutions you would need for your application, so grab what you need.
Werner Exinger wrote:
Again the guess value y:=1 will give you the bigger of the two solutions while a smaller guess like 0.01 will yield the solution for y which is closer to zero.
True. You could get both sets together by doing something like:
Alan
Yes. Exactly what i meant. Thanks. I'm now trying to apply the same concept to a different equation (almost same form as this one). I am actually trying to get used to plotting equations using Mathcad and Matlab.
I am getting it correctly with Matlab but i'm having some trouble drawing the graph and extracting the range of values of y. Could you please have a look? I'll be grateful. Thanks.
I'm trying to apply this concept to another equation(same form as above). I don't know what i'm doing wrong but i'm not getting the range of values of y that i'm supposed to get.
I also plotted the equation using Mathlab just to verify. I'll be grateful if you could have a look at it. Thanks.
