Hello Is the following method (attached image) of establishing a relationship between survival probability and force of mortality acceptable? Also I couldn't understand why the circled portion ( in the attached image) not taken into consideration. Thanks for your help!
Pretty much. However, in the first line where you have an integral, you should have d/ds (not d/dt) and there should be a ds on the end of the integral. By definition, o(h)/h tends to 0 as h tends to 0. So the term you have circled is 0.
