How to Differentiate a Function Handler Based on User Input

I would like to know how to differentiate or derive a function handler based on user input. I tried using diff but that doesn't work.

f = @(x) input
end

that's how i expect to get an input polynomial function from the user who run the program. I'm really new to matlab and now struggling to find the solution. Thanks for your answer.

[Ameer Hamza]

Can you tell what type of input can the user give?

[Timothy Wibisono]

i'm expecting the user to input a polynomial function, something like (5*x^3) or etc.

[Ameer Hamza]

Refer to my answer below.

Answer 1

[Ameer Hamza]

One solution is to use symbolic math toolbox

df = matlabFunction(diff(sym(f)));

[Timothy Wibisono]

Thanks, that works, but what if I'd also like to find the second derivative, or the derivative of df that you provided?

And, can i also find the integration within certain limits of a function handler based on user input?

[Ameer Hamza]

For the second derivative, there are two ways.

1) Since you already have function handle for df, you can get its derivative similarly.

df2 = matlabFunction(diff(sym(df)));

2) Or you can directly find the second derivative in the first step if you don't need the first derivative

df2 = matlabFunction(diff(sym(f), 2));

As far as integration is concerned, you can use integral() to directly integrate function handle.

[Timothy Wibisono]

thanks for your answer, it really helps.

[Ameer Hamza]

You are welcome.