Algebra 2 Unit 4 Notes: Laws of Exponents Polynomials and Real Number Operations Monomials: Exponents are used in expressions called monomials. A monomial is an expression that is a number, variable, or product of a number and one or more variables. Examples of monomials are 5c, - a, 17, 𝑥 3 , and Monomials cannot contain variables whose exponents cannot be written as whole numbers. (Exponents cannot be negative or fractions) Examples of expressions with exponents that are not monomials are Constants are monomials that contain no variables. The numerical factor of a monomial is the coefficient of the variable. For example the coefficient in -6m is -6. The degree of a monomial is the sum of the exponents of its variables. For example the degree of 12 𝑔7 ℎ4 is 7+4 or 11. The degree of a nonzero constant is 0. 1 2 𝑥4𝑦2. 1 1 𝑛 and √𝑛 = 𝑛2 2 Exponent Properties: Negative Exponents For any real number a, and any integer n, where a≠ 0, 𝑎−𝑛 = 1 1 𝑎𝑛𝑑 𝑎−𝑛 = 𝑎𝑛 . 𝑛 Multiplying Powers Dividing Powers For any real number a and integers m and n, 𝑎𝑚 ∙ 𝑎𝑛 = 𝑎𝑚+𝑛 . Properties of Powers Suppose m and n are integers and a and b are real numbers. Then the following properties hold. Power of a Power: (𝑎𝑚 )𝑛 = 𝑎𝑚𝑛 Power of a Product: (𝑎𝑏)𝑚 = 𝑎𝑚 𝑏 𝑚 For any real number a except a=0, and integers m and n, 𝑎 Product Property of Radicals Quotient Property of Radicals 𝑎𝑚 𝑎𝑛 = 𝑎𝑚−𝑛 . 𝑎𝑛 Power of a Quotient: (𝑏)𝑛 = 𝑏𝑛 , b≠ 0 For any real numbers a and b, and any integer n, n> 1, 𝑛 𝑛 𝑛 1. If n is even, then √𝑎𝑏 = √𝑎 ∙ √𝑏 when a and b are both nonnegative, and 𝑛 𝑛 𝑛 2. If n is odd, then √𝑎𝑏 = √𝑎 ∙ √𝑏 For real numbers a and b, b≠ 0, and any integer n, n> 1, 𝑛 𝑎 √𝑏 = 𝑛 √𝑎 𝑛 √𝑏 , if all roots are defined. To simplify monomials apply exponent properties. To simplify radicals apply radical exponent properties. Scientific Notation: Use exponents to express very large or very small numbers in base 10 using exponents. 𝑎 𝑥 10𝑛 , where 1≤ 𝑎 < 10 , and n is an integer. Number in scientific notation can be added, subtracted, multiplied, and divided. If 𝑛 ≥ 0, then number is greater than or equal to 1. If 𝑛 < 0, then the number is less than 1 but greater than 0. Polynomial: A polynomial is a monomial or a sum of monomials. The monomials that make up a polynomial are called the terms of the polynomial. A polynomial with three monomial terms is a trinomial. A polynomial with two monomial terms is a binomial. The degree of a polynomial is the degree of the monomial term with the largest degree. Polynomials can be added or subtracted by combining like terms. Polynomial Like Terms A monomial or a sum of monomials Terms that have the same variable(s) raised to the same power(s) Example: (2𝑥 2 + 3𝑥 − 4) + ( −3𝑥 3 + 4𝑥 2 − 6) = Use associative property to group like terms −3𝑥 3 + 2𝑥 2 + 4𝑥 2 + 3𝑥 − 4 − 6 = Combine like terms using Addition/Subtraction −3𝑥 3 + 6𝑥 2 + 3𝑥 − 10 Substitute simplified polynomial sum Example: (3𝑦 3 + 4𝑦 − 6) − (−4𝑦 4 + 2𝑦 3 − 5𝑦 2 + 2𝑦 − 8) = Change signs for subtraction and group 4𝑦 4 + 3𝑦 3 − 2𝑦 3 + 5𝑦 2 + 4𝑦 − 2𝑦 − 6 + 8 = Combine like terms 4𝑦 4 + 𝑦 3 + 5𝑦 2 + 2𝑦 + 2 Substitute simplified polynomial sum Polynomials can be multiplied by applying the distributive property or if you are multiplying two binomials, the FOIL method. FOIL Method of Multiplying Polynomials The product of two binomials is the sum of the products of F: the first terms. O: the outer terms. I: the inner terms. L: the last terms. Example: (𝑥 2 + 2𝑥 + 3)(𝑥 − 4) = Rewrite using distribution 𝑥(𝑥 2 + 2𝑥 + 3) − 4(𝑥 2 + 2𝑥 + 3) = Distribute the terms of the binomial to the trinomial 𝑥(𝑥 2 ) + 𝑥(2𝑥) + 𝑥(3) + (−4)𝑥 2 + (−4)2𝑥 + (−4)3 = Simplify 𝑥 3 + 2𝑥 2 + 3𝑥 − 4𝑥 2 − 8𝑥 − 12 = Substitute simplified polynomial 𝑥 3 + 2𝑥 2 − 4𝑥 2 + 3𝑥 − 8𝑥 − 12 = Group like terms using the associative property 𝑥 3 − 2𝑥 2 − 5𝑥 − 12 Substitute simplified polynomial sum Division of Polynomials: To divide a polynomial by a monomial, use the properties of exponents for quotients. To divide a polynomial by a polynomial, use a long division pattern. Remember that only like terms can be added or subtracted. If numerator is missing a term in descending order by degree, it must be replaced by zero to use long division. Synthetic Division: Synthetic division can also be used if the divisor is a binomial and the coefficient of the variable term is one and the exponent on the variable is one. Otherwise long division must be used. If the dividend is missing a term in descending order then zero must replace that term as a place holder. The following is an example of synthetic division. Pascal’s Triangle: Pascal’s triangle can be use for binomial expansion. The triangle follows the following pattern.