plot a function wit cos

here is my code but when i running it i get an error
f=(0:10);
%f0=5*10^9;
c=(3*10^8);
t=5*10^9;
w=2*pi*f;
wt=w*t;
k=(wt/c);
z=(0.75:30);
r12=0.29;
%x=0.094*cos*(k*z);
y=0.094*cos*(((100*pi)/3)*z);
%rin=abs(y);
plot(f,y);
xlabel("Frequency",'fontsize',5);
ylabel("|Γin|",'FontSize', 5);
title("Input reflection coefficient as a function of frequency","fontsize",7.5);
grid on;

that the errore

Error using cos
Not enough input arguments.

Error in project (line 11)
y=0.094*cos*(((100*pi)/3)*z);
i ty to fix it but tey stil have a erro at this line
 

Answer 1

[Torsten]

f=(0:10);
%f0=5*10^9;
c=(3*10^8);
t=5*10^9;
w=2*pi*f;
wt=w*t;
k=(wt/c);
z=(0.75:30);
r12=0.29;
%x=0.094*cos*(k*z);
y=0.094*cos(((100*pi)/3)*z);
%rin=abs(y);
plot(z,y);
xlabel("Frequency",'fontsize',5);
ylabel("|Γin|",'FontSize', 5);
title("Input reflection coefficient as a function of frequency","fontsize",7.5);
grid on;

[Yann]

thanks i fixed it

Answer 2

[Voss]

Maybe this

y=0.094*cos*(((100*pi)/3)*z);

should be this

y=0.094*cos(((100*pi)/3)*z);

or, without the extra parentheses:

y=0.094*cos(100*pi/3*z);

[Yann]

yes i see

thanks i fixed it