Here is bens reasoning for finding the upper and lower boundaries in which the actual area of his garden plot lies plot lies. Given measurements for length l and width w, the actual length is l + /-e and the actual width is w +/- e where e is the absolute error in each length measurement. So, the actual area lies between (l-e)(w-e) and (l+e)(w+e) i.e., between lw – e(l+w)+e2 and lw+e(l+w)=e2 .But e2 is negligible compared with other terms, so the actual area is lw+/-(w+l)e. Is his argument valid?

Question

Here is bens reasoning for finding the upper and lower boundaries in which the actual area of his garden plot lies plot lies. Given measurements for length l and width w, the actual length is l + /-e and the actual width is w +/- e where e is the absolute error in each length measurement. So, the actual area lies between (l-e)(w-e) and (l+e)(w+e) i.e., between lw – e(l+w)+e2  and lw+e(l+w)=e2 .But  e2 is negligible compared with other terms, so the actual area is lw+/-(w+l)e. Is his argument valid?

anonymous · Answer

i know the statement is true but why is it true i cant proove it my reasoning are not logical please help