Final answer:
To find the differential of a function at a point, you need to take the derivative of the function with respect to the independent variable and multiply it by the change in the independent variable. Using equations 4.5 and 4.6, you can find the derivatives of the position and velocity functions, respectively. Substitute the values of the point into the derivative to find the differential.
Step-by-step explanation:
The question asks for the differential of a function at a point using two equations. To find the differential, we need to take the derivative of the function with respect to the independent variable. The differential is then the derivative multiplied by the change in the independent variable. By using equations 4.5 and 4.6, we can find the derivative of the position function and the velocity function, respectively. Then, we substitute the values of the point into the derivative to find the differential.