Complex number with exponential

I am trying to solve this equation however matlab isn't returning any solution. The equation is as follow:

Y=2/(exp(Ci)+exp(-Ci)) where C is constant and i is the imaginary number

I tried using the complex function but it doesn't give correct answer when combined with exp.

[KSSV]

Solve the equation for what?

[Abdullah Azzam]

Just find the value of Y

[Walter Roberson]

Y = 2./(exp(C*1i)+exp(-C*1i))

In vectorized form.

Or

Y = 1./cosh(C)

Answer 1

[Walter Roberson]

Y = 1/cosh(C)
cosh(C) * Y = 1
cosh(C) = 1/Y
C = acosh(1/Y)