i need b value for every p using trial and error method

m=1.6;
r=1.4;
p=[1:1:14];

Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.

tan[p]=[2*cot[b]]*[[m.^2*sin[b]*sin[b]-1]/[m.^2[r+cos[2*b]]+2]];
disp(b)

[Torsten]

p is in degrees ?

[John D'Errico]

You are writing in the wrong language. Square brackets are not how you pass arguments into a function. You use () instead. I'd strongly suggest you start with the MATLAB Onramp tutorial, and learn basic MATLAB syntax.