Getting a blank graph

My assignment is to graph the output angular velocity of a given universal joint. I have the equation and I am told to graph the function over the interval (0,2pi) or 0 to 360 degrees. I don't know why but my code is giving me a blank graph. Here's my code :

 syms theta1  w1
grid on
theta1 = 0:pi/2:2*pi;

w2 = ((cos(pi/6)*(sec(theta1)).^2) / ((tan(theta1)).^2+(cos(pi/6)).^2))*2*pi;
plot(w2,theta1 ), xlabel('input angle'), ylabel('output velocity')

Answer 1

[Ameer Hamza]

grid on
theta1 = 0:pi/2:2*pi;
w2 = ((cos(pi/6)*(sec(theta1)).^2)./((tan(theta1)).^2+(cos(pi/6)).^2))*2*pi;
                                 %^ use elementwise division operator
plot(w2,theta1 ), xlabel('input angle'), ylabel('output velocity')