Identify a b , and a = 1 6 = 2 0 = 1 Find the axis of symmetry and sketch the line 20 2 (1 ) Ex - 1 The axis of symmetry is The * coordinate of the vertex is also - 1 Find the y - coordinate of the vertex ( ( 5 ) - ( - 1 ) + 2 - 1 ) + 6 The vertex is ( - 1 5 ) Since c = 6 , the y - intercept is ( O , 6 ) Reflect across the axis of symmetry to get ( - 2 6 ) a > O confirms the graph opens upward Domain : All real numbers . There is no restriction on the value of Range : 2 5 . since the minimum value of the function is 5