 31. ( 2 3 f x) x x2 = − + 4   2 ( 2x 3 f x) = −x + + ( ) 2x2 7 f x = − 30. ( 2x 3 f x) = − − +1)+ +1 2 4 x − (x  ( ) 2 7 49 f x  x2 x  = − + − 4 49 ( ( 4 − f x) x = − −1)2 + vertex: (1, 4)  2 16  8   x-intercepts: ( ) 2 f x = 7 2 81 − ( 0 4  x x − = − −1)2 + 8 ( 4 x −1)2 = vertex: 7 , 81  −  1 = ±2 x – = or = 3 x x –1 y-intercept: (0) (0) 2 f = − (0)2 3 3 + = The axis of symmetry is = 1. x
31.  f ( x) = 2 x − x2 + 3  4  2 30.  f ( x ) = 2x2 − 7 x − 4 f ( x) = −x f ( x) = − (x + 2x + 3 2 − 2x +1)+ 3 +1 f ( x ) = 2  x2 − 7 x + 49  − 4 − 49 f ( x) = − ( x −1)2 + 4 vertex: (1, 4)  2 16  8   x-intercepts: f ( x ) = 2  x − 7 2 − 81 8 0 = − ( x −1)2 + 4 ( x −1)2 = 4 vertex:  7 , − 81  x – 1 = ±2 x = –1 or x = 3 y-intercept: f (0) = 2 (0) − (0)2 + 3 = 3 The axis of symmetry is x = 1.
Precalculus-Essentials-5th-Edition-Blitzer-Solutions-Manual.docx