To find Z Parameters of network first open circuit the output terminal then I2 becomes Zero.
So equation are changed to
By calculating Equallant Resistance from the input side
((200+s) || 200)+((20000)/s)
∴
By substituting s=jω and ω=100rad/sec
From this 
By substituting s=jω and ω=100rad/sec
We can find Z12 and Z22 by open circuiting the input terminal and I1 becomes 0
So equation are changed to
Equallant Resistance from the output side
By substituting s=jω and ω=100rad/sec

105.88+j23.52
By substituting s=jω and ω=100rad/sec

