When I try to solve this equation, this message appears, how can I solve this problem?

k=2.7904;

R=0.20491;

syms a

Eqn=a./((1+(2.*k(1-a)))+((1+(2.*k./3)).*(sqrt(3.*(1-a)))))==R;

a = vpasolve(Eqn, a);

Invalid indexing or function definition. Indexing must follow MATLAB indexing.

Function arguments must be symbolic variables, and function body must be sym

expression.

Answer 1

[David Hill]

k=2.7904;
R=0.20491;
syms a 
Eqn=a./(1+(2*k*(1-a))+(1+(2*k/3)).*(sqrt(3*(1-a))))==R;%messed equation up (need k*(1-a))
s = vpasolve(Eqn, a);

[isra sahli]

thank you