cosine of a matrix returns weird values.

I'm trying to plot a few forces that chance because of an angle. I've defined the changing angle as beta which is a matrix. Than i'm calcultating two different angles which matter for the calculation of the forces. And for these forces i need, for example, the cosine of angle alpha. The angle of alpha changes between 90 and 0 degrees. But if i take the cosine of this matrix it returns weird numbers. Negative numbers, like -0.4481. It should start at 90 and cosine 90 equals 0 but it doesn't. Does anyone know what is going on?

Fad = 240

Fad = 240

beta = 0:1:180;                  % Angles                             
gamma = 180 - beta;                                          
alpha = 0.5.*gamma; 

w = cos(alpha);                 % Cosine and tanges of said angles
x = cos(gamma);
y = tan(alpha);
z = tan(gamma);

Fvloer1 = Fad./w;               % Calculations of different forces                                   
Fvloer2 = Fvloer1.*x;           % Almost all forces are matrices except for Fad which is a constant.                              
Fl = Fad.*y;                                                  
Ft = Fvloer2.*z;     

figure                          % Plots of these forces against an angle
plot(beta,Fvloer1)
xlabel("Hoek [Graden]")
ylabel("Kracht [N ]")
grid on

figure
plot(beta,Fvloer2)
xlabel("Hoek [Graden]")
ylabel("Kracht [N ]")
grid on

●

figure
plot(beta,Fl)
xlabel("Hoek [Graden]")
ylabel("Kracht [N ]")
grid on

figure
plot(beta,Ft)
xlabel("Hoek [Graden]")
ylabel("Kracht [N ]")
grid on

Answer 1

[Torsten]

"cos" and "tan" can be applied to angles in radians, not in degrees. Use "cosd" and "tand" instead.

[Wouter]

Came to the same conclusion, Thanks!