How to enforce a certain symbolic expression to appear in Equation

I have the following symbolic equation:

syms go u W d f

f = ((0.65*W)/go);

Fcc_1 = (2*5^(1/2)*d*go^2*(- (go^2*(u - 1)^2*W)/20 + W^3/8000)*(-(W^2/400 + ...

(u - 1)^2*go^2)/(W*go*(- 1 + u)))^(1/2))/(W*pi*(go^2*(u - 1)^2 + W^2/400)^2);

However, in the final equation (Fcc_1) I only want the variables 'u', 'd', and 'f' to appear. How can I enforce 'f' to be substituted accordingly?

Note that f is 0.65*W/go.

Answer 1

[Dyuman Joshi]

syms go u W d f

%relation of f with W, go
rel = ((0.65*W)/go)-f==0;

%Obtain W in terms of f and go (you can also get go in terms of f and W)
term = solve(rel,W)

term = 

Fcc_1 = (2*5^(1/2)*d*go^2*(- (go^2*(u - 1)^2*W)/20 + W^3/8000)*(-(W^2/400 + ...
    (u - 1)^2*go^2)/(W*go*(- 1 + u)))^(1/2))/(W*pi*(go^2*(u - 1)^2 + W^2/400)^2);

%Substitute the term in place of W in the main expression
out = subs(Fcc_1,W,term)

out = 

%Simplify the output
out = simplify(out)

out =