Algebra

"The idea behind teaching is to expect students to learn why things are true, rather than have them memorize ways of solving a few problems, as most of our books have done. [This] same philosophy lies behind the current text by Gelfand and Shen. There are specific 'practical' problems but there is much more development of the ideas ... [The authors] have shown how to write a serious yet lively look at algebra." -The American Mathematics Monthly "Were 'Algebra' to be used solely for supplementary reading, it could be wholeheartedly recommended to any high school student of any teacher ... In fact, given the long tradition of mistreating algebra as a disjointed collection of techniques in the schools, there should be some urgency in making this book compulsory reading for anyone interested in learning mathematics." -The Mathematical Intelligencer

• 1 Introduction.- 2 Exchange of terms in addition.- 3 Exchange of terms in multiplication.- 4 Addition in the decimal number system.- 5 The multiplication table and the multiplication algorithm.- 6 The division algorithm.- 7 The binary system.- 8 The commutative law.- 9 The associative law.- 10 The use of parentheses.- 11 The distributive law.- 12 Letters in algebra.- 13 The addition of negative numbers.- 14 The multiplication of negative numbers.- 15 Dealing with fractions.- 16 Powers.- 17 Big numbers around us.- 18 Negative powers.- 19 Small numbers around us.- 20 How to multiply am by an, or why our definition is convenient.- 21 The rule of multiplication for powers.- 22 Formula for short multiplication: The square of a sum.- 23 How to explain the square of the sum formula to our younger brother or sister.- 24 The difference of squares.- 25 The cube of the sum formula.- 26 The formula for (a + b)4.- 27 Formulas for (a + b)5, (a + b)6,... and Pascal’s triangle.- 28 Polynomials.- 29 A digression: When are polynomials equal?.- 30 How many monomials do we get?.- 31 Coefficients and values.- 32 Factoring.- 33 Rational expressions.- 34 Converting a rational expression into the quotient of two polynomials.- 35 Polynomial and rational fractions in one variable.- 36 Division of polynomials in one variable; the remainder.- 37 The remainder when dividing by x - a.- 38 Values of polynomials, and interpolation.- 39 Arithmetic progressions.- 40 The sum of an arithmetic progression.- 41 Geometric progressions.- 42 The sum of a geometric progression.- 43 Different problems about progressions.- 44 The well-tempered clavier.- 45 The sum of an infinite geometric progression.- 46 Equations.- 47 A short glossary.- 48 Quadratic equations.- 49 The case p =. Square roots.- 50 Rules forsquare roots.- 51 The equation x2 + px + q =.- 52 Vieta’s theorem.- 53 Factoring ax2 + bx + c.- 54 A formula for ax2 + bx + c = (where a ? 0).- 55 One more formula concerning quadratic equations.- 56 A quadratic equation becomes linear.- 57 The graph of the quadratic polynomial.- 58 Quadratic inequalities.- 59 Maximum and minimum values of a qua ratic polynomial.- 60 Biquadratic equations.- 61 Symmetric equations.- 62 How to confuse students on an exam.- 63 Roots.- 64 Non-integer powers.- 65 Proving inequalities.- 66 Arithmetic and geometric means.- 67 The geometric mean does not exceed the arithmetic mean.- 68 Problems about maximum and minimum.- 69 Geometric illustrations.- 70 The arithmetic and geometric means of everal numbers.- 71 The quadratic mean.- 72 The harmonic mean.