Finding the Domain of Radical Functions 1.3 2006/02/02 22:44:49 US/Central 2006/04/27 15:34:08.878 GMT-5 Pradnya Vinay Bhawalkar pradnyab89@gmail.com Kim Dodge Johnston kim.johnston@fortbend.k12.tx.us Pradnya Vinay Bhawalkar pradnyab89@gmail.com Domain function Radical restriction root Finding the domain of radical/root functions. When finding the domain of even-degree roots, the expression under the radical must be greater than or equal to 0.Find the domain of y x x x 0 PRACTICE - Find the Domain of the following: y 2x5 x x 52 since 2x5 0 , 2x 5 , x 52 y 4 7x x x 7 since 7x 0 , x 7 , x 7 The rest of the answers will be expressed in interval notation since that is a simpler way to express answers. y 4 4x216 2 2 since 4x216 0 , 4 x2 16 , x2 4 , x 2 x 2 y 16 25 x 2 45 45 since 16 25 x2 0 , -25 x2 -16 , x2 1625 , x 4 5 x 4 5 y x 7 x 1 1 7 , x 7 x 1 0 y 2 x 2 7 x 3 12 3 , 2 x 2 7 x 3 0 , 2 x 1 x 3 0 , x 1 2 x 3 y x x 2 4 , since x 2 4 0 , x 2 4 This will always be true, for all real numbers, any number squared is always positive y x x8 8 since x 8 0 , x 8 , x 8 y 6x28 , since 6 x 2 8 0 , 6 x 2 8 , x 2 -86 This will always be true, for all real numbers, any number squared is always positive y 86x2 No solution since 8 6 x2 0 , -6 x2 8 , x2 -86 This will never be true, so there is no solution, since any number squared is always positive, so it will never be less than 0.