How to find the maximum of symbolic equation which contains trigonometric terms?

I am trying to find the maximum value of "P" in the following equation with respect to "theta". ""dP/dtheta = 0""

P = 0.5*gama*((H)^2)*(1-kv)*Kgama + q*H*(1-kv)*Kq

where

Kgama=((1+tan(beta)*tan(g))*tan(beta)+((1+tan(beta)*tan(g))^2/(tan(theta)-tan(g))))*((sin(theta-phi)+tan(psi)*cos(theta-phi))/(cos(beta+delta-theta+phi)));

Kq = (b/H)*cos(g)*((sin(theta-phi)+tan(psi)*cos(theta-phi))/(cos(beta+delta-theta+phi)));

[Torsten]

My first step would be to give values to the other parameters and plot P as a function of theta.

Answer 1

[Torsten]

syms gama H kv q beta phi g theta psi delta b
P = 0.5*gama*((H)^2)*(1-kv)*((1+tan(beta)*tan(g))*tan(beta)+((1+tan(beta)*tan(g))^2/(tan(theta)-tan(g))))*((sin(theta-phi)+tan(psi)*cos(theta-phi))/(cos(beta+delta-theta+phi)))+ q*H*(1-kv)*(b/H)*cos(g)*((sin(theta-phi)+tan(psi)*cos(theta-phi))/(cos(beta+delta-theta+phi)));
dPdtheta = diff(P,theta);
sol = simplify(solve(dPdtheta==0,theta))

sol = 

[Akshay Pratap Singh]

Thank @Torsten for the help.