How can I find the determinant of a matrix with an unknown variable?

I have a 4*4 matrix which I'm trying to calculate the determinant for to find the value of variable "omega" how can I do that through matlab?

Thank you

Example

omega21=[0 1 0 1;((-mc*omega21^2)+k)*sinh(beta1*L/2)... +(E*I*beta1^3*cosh(beta1*L/2)) ((-mc*omega2^2)+k)*cosh(beta1*L/2)... +(E*I*beta1^3*sinh(beta1*L/2)) ((-mc*omega2^2)+k)*sin(beta1*L/2)... +(E*I*beta1^3*cos(beta1*L/2)) ((-mc*omega2^2)+k)*cos(beta1*L/2)... +(E*I*beta1^3*sin(beta1*L/2));sinh(beta1*L) cosh(beta1*L) sin(beta1*L)... cos(beta1*L);E*I*beta^2*sinh(beta*L) E*I*beta^2*cosh(beta*L) -E*I*beta^2*sin(beta*L) -E*I*beta^2*cos(beta*L)]