3x2 + 18x = 0 −b −(−8) = = = 8 = 2 . x + = 3x( 6) 0 x The are by solving: x-intercepts 2a 2(2) 4 = 0 or = −6. x x The of the vertex is y-coordinate The are 0 and −6 . x-intercepts − = 64 > 0, ⎛ −b ⎞ = (2) = 2(2)2 − 8(2) = 8 − 16 = b2 f f 4ac = −8. ⎝ ⎠ (−8)2 The is y-intercept Thus, the vertex is (2, − 8) . − The axis of symmetry is the line = 2 . x (0) = 0 . f The discriminant is:
x = −b = −(−8) = 8 = 2 . The x-intercepts are by solving: 3x2 + 18x = 0 3x( x + 6) = 0 2a 2(2) 4 x = 0 or x = −6. The y-coordinate of the vertex is The x-intercepts are 0 and −6 . f ⎛ −b ⎞ = f (2) = 2(2)2 − 8(2) = 8 − 16 = −8. ⎝ ⎠ Thus, the vertex is (2, − 8) . The axis of symmetry is the line x = 2 . The discriminant is: b2 − 4ac = (−8)2 − = 64 > 0, The y-intercept is f (0) = 0 .