Help solving an equation iteratively

Help solving an equation iteratively - Messages

#1 Posted: 9/8/2017 10:26:49 AM
drewbagel423

drewbagel423

0 likes in 4 posts.

Group: User

I have the equation 0.005*N^-0.12 + 0.565*N^-0.46 = 0.010 that I am trying to solve for N. I know the answer is ~9500 but I do not know how to solve it using SMath Studio. I tried "solve" but I get the "No real roots" error.
#2 Posted: 9/8/2017 11:27:51 AM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Wrote

I have the equation 0.005*N^-0.12 0.565*N^-0.46 = 0.010 that I am trying to solve for N. I know the answer is ~9500 but I do not know how to solve it using SMath Studio. I tried "solve" but I get the "No real roots" error.



As simple as that: plot first to check if there is intersection
between the two functions. You don't solve for a constant, you
solve for a constant defined as a function. Next, guesstimate
for bracketing the solve block ... done.

Cheers collab.

Solve Unknown.PNG

#3 Posted: 9/8/2017 12:04:08 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

... your project from iterative Dichotomy

Solve Dichotomy.sm (9 KiB) downloaded 49 time(s).
#4 Posted: 9/8/2017 12:27:18 PM
drewbagel423

drewbagel423

0 likes in 4 posts.

Group: User

Wrote

Wrote

I have the equation 0.005*N^-0.12 0.565*N^-0.46 = 0.010 that I am trying to solve for N. I know the answer is ~9500 but I do not know how to solve it using SMath Studio. I tried "solve" but I get the "No real roots" error.



As simple as that: plot first to check if there is intersection
between the two functions. You don't solve for a constant, you
solve for a constant defined as a function. Next, guesstimate
for bracketing the solve block ... done.

Cheers collab.

Solve Unknown.PNG



Works perfectly. Thanks!
#5 Posted: 9/8/2017 2:33:46 PM
Davide Carpi

Davide Carpi

1416 likes in 2873 posts.

Group: Moderator

Wrote

I tried "solve" but I get the "No real roots" error.


probably you have used solve(2) (function with 2 arguments) that is driven by the global parameters (tools > options > calculation > roots (range)) and is designed mainly for solutions on the fly.

use instead solve(4), giving an adequate range (f.e. by plotting the function, as mentioned above by Jean)

2017-09-08 19_29_43-SMath Studio - [Page1_].png
If you like my plugins please consider to support the program buying a license; for personal contributions to me: paypal.me/dcprojects
  • New Posts New Posts
  • No New Posts No New Posts