The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r₁ = Minimum radius of the cam, r₂ = Radius of the roller follower and $$\theta $$ = Angle turned by the cam from the beginning of the follower displacement)

A. $$\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)\left( {1 - \cos \theta } \right)$$

B. $$\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)\left( {1 + \cos \theta } \right)$$

C. $$\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)\left( {\frac{{1 - \cos \theta }}{{\cos \theta }}} \right)$$

D. $$\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)\left( {\frac{{1 - \cos \theta }}{{\cos \theta }}} \right)$$

Answer: Option D