Recent content by becu

bump! i just need hint. thanks

Homework Statement Suppose that if k is a measurable function and {x : k(x) > 0} has a positive measure, then {x : k(x) >= p} has positive measure for some p > 0 Homework Equations Lebesgue measureThe Attempt at a Solution What is positive measure? is it just another word for measurable? Can I...

sorry for bumping this old topic. I'm reading this section right now and I'm very confused. can some one give me a notation for definition of k-topology? may be an example? the book said basis is the interval (a,b), along with sets (a,b) - K where K is stated above. What the difference between...

then? we're using this fact to prove when the case u is complex-valued function right? I got that part down, put I'm stuck when u is real-valued function. actually when I read further down, the book suggest to use mean-value property to prove above statement.

Variation of Maximum principle: "If u(x,y) is harmonic and nonconstant on a domain D, then |u(x,y)| has no local maximum in D". the proof of this is left as an exercise. i want to prove it. case 1: u(x,y) is complex-valued function, then since u is harmonic, it is analytic on D. By the Maximum...

Hi, I'm studying complex analysis right now, I would like to use this thread to ask questions when I read books. Many questions will be very stupid, so please bear with me. Also, English is my second language. text: Complex Analysis (2nd edition) author: Stephen D. Fisher [question deleted]...