Here we linearize the nonlinear modeling equations to find the state space form

where the state, input, and output vectors are, in deviation form

recall that our two dynamic equations are

The elements of the state-space A matrix are found by

The elements of the B matrix are found by

Since both states are measured, the C matrix is I. The numerical values for the matrices are

B. Wayne Bequette, bequeb@rpi.edu