In: Advanced Math
Analysis Integral confused concept. Please clear writing and follow the comment
1. upper sum with respect to P is U(f,P)= sum of Mk(xk-xk-1). Does that equal to U(f)=inf{u(f,P): p is a element of Q} (Q is the collection of all possible partition})
Also, is Mk=sup{f(x):x is a element of {xk-1,xk}?????
2. If Q is a refinement of P, then U(f, Q)<=U(f, P) and L(f, P),<=L(f,Q). I don't understand the geometric meaning behind this because Q has more element than P and contains all of the elements from P, However, why U(f, Q)<=U(f, P)????
This Q is not the Q from question1