Numeric Derivative - problem entering df

Hi,
I have a function (e(1)^(cos(x^2))+ln(1+x^2)...I derived it correctly to (2*x/1+x^2)-2*x*sin(x^2)*(e(1)^cos(x^2))
Then I tried to enter it to Matlab in this form:
df=(2*x./(1+x.^2))-(2*x.*sin(x.^2)*exp(1)^(cos(x.^2)))
But I am still having this error: Error using ==> mpower Inputs must be a scalar and a square matrix. To compute elementwise POWER, use POWER (.^) instead.
I really don't know where else I have to put the dots...
Can somebody fix this expression, please ??
Thanks a lot

 Risposta accettata

Azzi Abdelmalek
Azzi Abdelmalek il 7 Mag 2013
Modificato: Azzi Abdelmalek il 7 Mag 2013
df=2*x./(1+x.^2)-2*x.*sin(x.^2).*exp(1).^cos(x.^2)

Più risposte (1)

Matlab is complaining about the "*" operator just after "sin(x.^2)". It should be ".*". Also you should be using matlab's 'exp' function:
df=(2*x./(1+x.^2))-(2*x.*sin(x.^2).*exp(cos(x.^2));

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