Thread: mathematical problem in Physics

The total work done by the force as the object moves from position x1 to xn can be approximated by the formula

What is meant by (i) in this?
Is it first middle or last value? Below the sigma it is (i=1) but in graph it is in middle.
kindly explain.

http://www.staff.amu.edu.pl/~romangoc/M7-work-variable-force.html

The i value runs from 1 and n (in this example) and you substitute whatever i value you're on into the part to the right of the symbol.

The symbol is a way of simplifying a long addition problem.

Lets do an example using the formulas you've been given.
Lets say n=5. This means that there will be 5 values of to consider.

Let the first one be called , the second etc up to .

Then what does is we start at i=1 and add together all values from up to which in this case is 5.

So we get .