what is the vertex form of f(x)=3x^2-18x+8 by completing the square

Question

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Answer 1

f(x) = 3x² - 18x + 8

 

      = 3(x² - 6x) + 8 = 3(x² - 6x + 9 - 9) + 8

 

                               = 3(x-3)² - 27 + 8

 

                               = 3(x-3)² - 19

 

                               = 3(x-3)² + (-19)

 

     Vertex = (3,-19)