how to solve a trigonometric equations

f(x)=1+cosh^2(x)+2*cos(x)*cosh(x)-sinh^2(x)=0

how can i solve this equation.

[KSSV]

Copy your code.....not an image snippet.

Answer 1

[Bjorn Gustavsson]

If you are a matlab-beginner I suggest you read through the getting started-type documentation, that you work yourself through demos and browse through the help.

To solve these kind of equations you can go, at least, 2 ways either try to solve the equation symbolically, or numerically.

If you try for analytical solutions you have to declare your variable to be symbolic:

sym x
% then maybe you can get a set of solutions to the equation:
X_sol = solve(0==1 + cosh(x)^2 + 2*cos(x)*cosh(x)-sinh(x));

If that fails you'll have to resort to numerical solutions. Have a look at fsolve:

help fsolve

HTH