Recent content by vantroff

Just using the fact that my post is at the top... Thanks for the fast answer!

Hi, the question is from Serge Lang - Basic mathematics, Page 171 exercise 6. Thing to prove: Let ΔPQM and ΔP'Q'M' be right triangles whose right angles are at Q and Q', respectively. Assume that the corresponding legs have the same length: d(P,Q)=d(P',Q') d(Q,M)=d(Q',M') Then the right...

Thank you for the answer! I think that I understand it now. IDK why in all the books where I checked it wasn't explained that simple (it wasnt explained at all)...

I've seen in books things like "G is mapping of plane into itself", "map of a set into itself" or "map of set/plane onto itself". What exactly to map into/onto itself means? Do this means that when G maps into itself we get G as a result or we can also associate points on G to other points as...

I'll definitely look for older edition... I've seen the "Contents" of the book, a picture from Chapter 5 and 7 would be good. Thanks in advance!

Sorry that I didn't made it clear. I want something that will give me enough problems to solve so I will be ready to move from Lang's "Basic mathematics" and I.M. Gelfand - "Trigonometry" to something more advanced because I am getting closer to the part of my Physics book where I will need...

These look really good, considering the amount of positive reviews in Amazon, the topics it covers and that you are recommending it. I will probably buy the one about precalculus and something about trigonometry, and something about geometry... The prices are very reasonable, I was expecting...

Hi, I need book with examples(and the solutions) that will help me to practice the things I learn from Serge Lang-Basic Mathematics. I don't know how exactly these are called in English. Workbooks? It's not necessary to be book only with problems, it can be something like this one but with more...

Because how the distributive, associative and commutative properties work. And where they work. (at least that what I think) (ab)2 = a2b2 Why? Because (ab)2 means (ab)*(ab)=ab*ab=aa*bb=a2b2 But, (a+b)2 = (a+b)(a+b)=a(a+b)+b(a+b)=a2+ab+ba+b2=a2+2ab+b2 ≠ a2+b2 We can think for the thing in the...