... no thuc su rat don gian, quyen ru va ban khong can phai "hoc vet" nhieu dinh ly de co the giai duoc chung Khi hoc bat dang thuc, hai dieu cuon hut chung ta nhat chinh la sang tao va giai bat dang ... Pham Thi Hang December 26, 2008 ii Copyright c 2008 by Vo Quoc Ba Can Preface "Life is good for only two things, discovering mathematics and teaching mathematics." S Poisson Bat dangthuc la mot ... chinh la sang tao va giai bat dangthuc Nham muc dich kich thich su sang tao cua hoc sinh sinh vien nuoc nha, dien dan mathsvn da co mot so topic sang tao bat dangthuc danh rieng cho cac ca nhan...