²⁷Even without linearisation, we can calculate everything for a circuit, although the complexity increases a lot. For the circuit in Figure 3.3, the collector current for a sinusoidal input signal is $i_C=I_{C0}\cdot \left(e^{q\cdot (V_{\mathit{BE}}+V_{\mathit{be}}\cdot \mathit{sin}(\mathit{\omega t}))∕\mathit{kT}}\right)$: rather unreadable and complex. The Taylor series expansion of this gives the DC-current, the fundamental harmonic and all harmonic distortion components. This method is rather cumbersome. For circuits containing multiple transistors, such calculations quickly become impossible.
One of the solutions to cope with this impossibility to calculate analytically is simulating numerically, which usually gives very little insight: you only obtain a number and no relation which would reveal the relation (duh) between various parameters.