what is wrong in this code

syms t;
y=(3.7).*(10).^17;
y=3.88*(10).^16.*(t).^(1.5).*exp(-7000./t);
k=solve(y);

[Stephen23]

@Angad Singh Agarwal: I formatted your code correctly by selecting the code text and then clicking the {} Code button. Next time you can do this yourself.

Answer 1

[sjoerd]

Althought it is not completely clear to me what your question/problem exactly is, I will give it a try I assumed that you want to solve the following equation for t:

3.7e17 = 3.88e16*(t)^(1.5)*exp(-7000./t)

Please note the use of 'e' for the scientific notations which makes its way shorter. Next to this I removed the dots because no need to solve this element wise (only scalar calculations).

The main problem with your code is that you first assign a value to to 'y' and then overwrite this value with the full equation. So introducing a different variable gives the following.

syms t;
result=3.7e17;
y=3.88e16*(t)^(1.5)*exp(-7000/t);
k=solve(y==result);

And this solves for t, (it will give warning that it is not symbolically solved but a numerical approximation is used).

    k = 833 (approximately)

[Angad Singh Agarwal]

thanks a lot.

[Angad Singh Agarwal]

showing following error

??? Error using ==> char
Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189
   vc = char(v);

Error in ==> solve at 67
[eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4
k=solve(y==result); 
??? Error using ==> char
Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189
   vc = char(v);

Error in ==> solve at 67
[eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4
k=solve(y==result); 
??? Error using ==> char
Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189
   vc = char(v);

Error in ==> solve at 67
[eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4
k=solve(y==result);

[sjoerd]

I think you need to give us a little bit more information, which Matlab version do you use? I am using R2015a and it works fine. Furthermore showing a single error stack is also fine ;)

Answer 2

[Torsten]

syms t
result=3.7e17;
y=3.88e16*(t)^(1.5)*exp(-7000/t);
k=solve(y==result,t);

Best wishes

Torsten.

[Angad Singh Agarwal]

https://in.mathworks.com/matlabcentral/answers/324564-what-is-wrong-in-this-code#answer_254544 getting following error:

??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t); ??? Error using ==> char Conversion to char from logical is not possible.

Error in ==> solve>getEqns at 189 vc = char(v);

Error in ==> solve at 67 [eqns,vars] = getEqns(varargin{:});

Error in ==> Untitled2 at 4 k=solve(y==result,t);

[Torsten]

You seem to use an older MATLAB version.

Take a look into your documentation to see how to use "solve" for your release.

Best wishes

Torsten.