The fundamental equation for correct steering is (where $$\varphi $$ and $$\alpha $$ = Angle through which the axis of the outer wheel and inner wheel turns respectively, c = Distance between the pivots of the front axles and d = Wheel base)

A. $$\sin \varphi + \sin \alpha = \frac{{\text{b}}}{{\text{c}}}$$

B. $$\cos \varphi - \sin \alpha = \frac{{\text{c}}}{{\text{b}}}$$

C. $$\cot \varphi - \cot \alpha = \frac{{\text{c}}}{{\text{b}}}$$

D. $$\tan \varphi + \cot \alpha = \frac{{\text{b}}}{{\text{c}}}$$

Answer: Option C