x2 = 0 Solve for x by taking the square root of both sides. Check x2 = 121 (11) x2 = 121 (–11) Substitute 11 and –11 into the original equation.ġ1 Substitute 0 into the original equation.Ĭheck It Out! Example 1b Solve using square roots. x2 = 121 Solve for x by taking the square root of both sides. There is no real solution.ġ0 Substitute 11 and –11 into the original equation.Ĭheck It Out! Example 1a Solve using square roots. x2 = –49 There is no real number whose square is negative. Check x2 = 169 (13) x2 = 169 (–13) Substitute 13 and –13 into the original equation.ĩ Example 1B: Using Square Roots to Solve x2 = a x2 = 169 Solve for x by taking the square root of both sides. This is indicated by ±√ Positive and negative Square roots of 9Ħ The expression ☓ is read “plus or minus three”Ĩ Example 1A: Using Square Roots to Solve x2 = a Recall from Lesson 1-5 that every positive real number has two square roots, one positive and one negative.ĥ Positive Square root of 9 Negative Square root of 9 When you take the square root of a positive number and the sign of the square root is not indicated, you must find both the positive and negative square root. Square roots can be used to solve some of these quadratic equations.
Some quadratic equations cannot be easily solved by factoring. x = 10 x = 80 x = 20ģ Objective Solve quadratic equations by using square roots.Ĥ Some quadratic equations cannot be easily solved by factoring
Warm Up Lesson Presentation Lesson Quiz Holt McDougal Algebra 1 Holt Algebra 1Ģ Warm Up Find each square root. Presentation on theme: "Solving Quadratic Equations by Using Square Roots 9-7"- Presentation transcript:ġ Solving Quadratic Equations by Using Square Roots 9-7