how to use the subs syntax for the two variable

syms x a

series1(x) = a+(2/3)*a*x+(5/3)*a^2*x^2+(1/3)*a^3*x^3

a=0.56

series2(x)=subs(series1,a,0.56)

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when is use the subs synatx to replace the value of a in series1 it is not replacing the vlue of a .

So what the problem with the synatx?

Since series1 is the function of x only so it is not replacing the value a ?

If yes how should I substuite the value of a so that series1 contain only variable x .

Answer 1

[Dyuman Joshi]

"when is use the subs synatx to replace the value of a in series1 it is not replacing the vlue of a ."

When you define a=0.56, it overwrites a from symbolic variable to a double variable and thus you can not use it in subs()

There is no need of the line a=0.56. You can directly substitute the value.

In case you want to use a variable to store the value and then substitute, do not name it the same as the symbolic variable, use a different name such as - A or a0 or a_0 etc.

syms x a 
series1(x) = a+(2/3)*a*x+(5/3)*a^2*x^2+(1/3)*a^3*x^3

series1(x) = 

series2(x)=subs(series1,a,0.56)

series2(x) = 

Answer 2

[yogeshwari patel]

Thank you