Algebra 1 Notes SOL A.3 Radicals Mr. Hannam Name: _______________________________________ Date: _______________ Block: ________ Radical Review A perfect square is ________________________________________________________________. The first 12 perfect squares are: ___________________________________________________. A square root of a number is ______________________________________________________. Find: Estimating square roots: find the closest perfect square 36 49 33 144 o Estimate to the nearest whole number: The By default, take the square root. Example: 35 55 99 symbol is called a radical. The number inside is the radicand. 42 4= 2 Simplifying Radicals A radical expression is in simplest form if: No perfect squares other than 1 are in the radicand No fractions are in the radicand No radicals appear in the denominator of a fraction We use the Product Property of Radicals and Quotient Property of Radicals to simplify: Product Property of Radicals The square root of a product equals the product of the square roots of the factors: ab a b Example: 4 9 4 9 Quotient Property of Radicals The square root of a quotient equals the quotient of the square roots of the a a numerator and denominator: b b Example: Method 1: Prime Numbers Find prime factors of the radicand Remember that Example: Reduce 36 36 4 4 a • a a for any number a 24 1) Find prime factors: 24 2 2 2 3 2) Therefore: 24 2 2 2 3 Look for pairs of the same number! 2 2 23 2 2 23 2 23 2 6 3) Reduced: 24 2 6 You try: Simplify 32 using prime factor method Algebra 1 Notes SOL A.3 Radicals Mr. Hannam Page 2 Method 2: Product of Perfect Squares Re-write the radicand as the product of perfect squares, and then take the roots of those perfect squares. 1) Know your perfect squares (it is helpful to write a list: _____________________________) 2) Find the biggest perfect square that is a factor of that number, and write the radicand as a product 3) Take the square root of the perfect square, leaving the other factor inside the radical Example: Reduce The biggest perfect square that is a factor of 24 is 4 Rewrite: 24 4 6 Use Product Property and take square root: You try: Simplify 24 24 4 6 4 6 2 6 32 using the product of perfect square method If the radicand is a fraction, “split up” the radical into the numerator and denominator, and then simplify 13 Example: Simplify 100 13 13 o “Split up”: 100 100 o Simplify numerator and denominator. Put in simplest form. 18 o You Try: Simplify 4 You try: Simplify the radical expressions – use both methods! a) 81 b) 48 c) 75 d) 20 9 Rationalizing Denominators The process of eliminating a radical in a denominator is called rationalizing the denominator. Remember that a) Example: a • a a for any number a 5 5 7 5 7 7 7 7 7 b) You try: 2 5 (Hint: simplify all radicals first!) 24 You try: Simplify the radical expressions… a) 20 b) 72 c) 28 d) 9 16 e) 1 2 f) 6 12