Mahdim
Hi
i am studying this book (Introductory Functional Analysis book) and was not able to solve the problem 12 of section 1.1 on page 9 of the Functional Analysis book of Erwin Kreyszig, it is simple but i am a bit silly on this :
(Triangle inequality) The triangle inequality has several useful conse-quences. For instance, using (1), show that:
|d(x, y)-d(z, w)| <= d(x, z)+d(y, w).
i am studying this book (Introductory Functional Analysis book) and was not able to solve the problem 12 of section 1.1 on page 9 of the Functional Analysis book of Erwin Kreyszig, it is simple but i am a bit silly on this :
(Triangle inequality) The triangle inequality has several useful conse-quences. For instance, using (1), show that:
|d(x, y)-d(z, w)| <= d(x, z)+d(y, w).