How can we precise the substituted values (to 04 numbers )after differentiation?

I have differentiated the polynomial equation and have substituted the values to the variables. But I need to precise the values. Can any one please provide with answer?

[Naga Ranjith Kumar Addagalla]

I am thankful for your answer. As I have solved by myself, I haven't seen the reply earlier. Please apologize.

Answer 1

[Maitreyee Mordekar]

I assume that you are using MATLAB 2016a version. I have a small code snippet that I think is your concern.

 syms x;
 y=x.^3;
 z=diff(y,1);
 x1=3.0912345678;
 z1=subs(z,x1);

This would display the z1 as a fraction. Just convert the z1 variable to a floating number precision. You may use single or double point precision.

 z2=single(z1);  %Single precision
 z3=double(z1);  %Double precision

This should return the result in a numeric format with the precision according to the double or single data type.

In case you can afford to stay in the symbolic domain, you may use the variable-precision arithmetic. The result will be a symbolic data and not a numeric one.

 z4 = vpa(z1,10);

You may refer to variable precision arithmetic for the documentation.

Hope it helps.