6.3 Notes Fisher Algebra 2 6.3 Notes Name: Date: MARCH Pd: 9 6.3 – Binomial Radical Expressions WARM-UP Try This!!! Simplify. 3𝑟 − 2𝑎 + 3𝑟 2 + 5𝑟 − 10𝑑 + 14𝑎 I. Adding and Subtracting Radicals To simplify the previous expression, you may only combine LIKE terms. Similarly, there must be LIKE RADICALS to combine radicals. Like Radicals:_____________________________________________________________ √2 radicand Examples of: Like Radicals: √2 √2 Unlike radicals: √5 √2 √3 TEACHER DO Examples Simplify. 1. 3√2 + 5√2 √2 Step 1: Take out what they have in common; take out like radical (3 + 5) √2 Step 2: Add the coefficients 8√2 2. √8 + √98 √8= √4 + √2 √98= √49 + √2 = 2 √2 + 7 √2 = (2+7) √2 = 9 √2 1 6.3 Notes Fisher 3 3 3. √81 − √24 3 3 3 (√33 · √3) = √81 Step 1: Factor & Reduce/Simplify (27·3 = 81) 3 3 3 ( √2³ · √3) = √24 (8·3) = 24 3 3 3√3 - 2 √3 = Step 2: Take out like radical 3 (3-2) √3 = Step 3: Subtract the Coefficients 3 √3 3 4. 2√5 + 3√5 Can Not Add- Index is Different, therefore already simplified 3 3 5. √27 − √8 3 3 √3³ − 1√8 3 (3-1) √8 3 2√8 STUDENTS DO 7. √27 + √12 − √75 8. √245 + 3√125 10. 3 3√3𝑥𝑦 + 3√24𝑥𝑦 11. √48 + √162 4 4 3 3 3 9. √250 − √54 + √4 12. √81𝑥 + √64𝑥 2 6.3 Notes Fisher TEACHER DO II. Distributing. We can also distribute with radicals. 1. Multiply Using FOIL, First, Outer, Inner, Last 2. Combine Like Terms 8. √6(√2 + √3) √6 ·√2 = √12 + √6 · √3 = √18 9. (2+√3) (3√2- √5) FOIL 2·3√2 - 2√5 + √3 ·3√2 - √5·√3 6√2 - 2√5 + 3√6 -√15 = √12 + √18 10. (3 + √5)² (3 + √5) (3 + √5) = 9+ 3 + √5 +3 + √5 + 5 First Step: Foil =(9+5) + (3+3)√5 Second Step: Combine like Terms = 14 + 6√5 3 6.3 Notes Fisher STUDENTS DO III. Multiplying Binomials Containing Radicals. 1. 5 3. 3 3 2 3 FOIL 6 116 11 FOIL 6. (√3 − √5)(2√3 − 5√5) FOIL 2 2. ( 7 11) FOIL 4. 7 2 5 7 2 5 FOIL 7. (2 − 2√3)(2 − 2√3) FOIL 4 6.3 Notes Fisher TEACHER NOTES Conjugates: Are binomial expressions that differ only in the sign of the second term. Example: √3 + √2 and √3 - √2 rational number *The product of Conjugates is always an (√2 + √3 ) (√2 + √3 ) 2-√6 + √6 -3 = -1 What is the conjugate of 2 3 ? √2 - √3 of 2 5 4 3 ? 2√5 + 4√3 The idea of conjugates can be valuable when we need to rationalize a denominator. IV. Rationalizing a denominator with a binomial. TEACHER DO 6. 6 3-√5 18- 6√5 18- 6√5 3 + √5 3-√5 3²- (√5)² 9-5 · = = = 18- 6√5 4 = 9-3√5 2 STUDENTS DO 2 + √3 7. 1 - √3 Step #1: FOIL Step #2: Combine Like Terms 5