What is the vertex of y= -2x^2-2x-6+3(x-1)^2? Algebra Quadratic Equations and Functions Quadratic Functions and Their Graphs 1 Answer Jothi S. Dec 9, 2015 y=(x-4)^2-19 Explanation: y=-2x^2-2x-6+3x^2-6x+3 y=x^2-8x-3 Use completing square y+16=x^2-8x+4^2-3 y+16=(x-4)^2-3 y=(x-4)^2-19 Answer link Related questions What are the important features of the graphs of quadratic functions? What do quadratic function graphs look like? How do you find the x intercepts of a quadratic function? How do you determine the vertex and direction when given a quadratic function? How do you determine the range of a quadratic function? What is the domain of quadratic functions? How do you find the maximum or minimum of quadratic functions? How do you graph y=x^2-2x+3? How do you know if y=16-4x^2 opens up or down? How do you find the x-coordinate of the vertex for the graph 4x^2+16x+12=0? See all questions in Quadratic Functions and Their Graphs Impact of this question 1568 views around the world You can reuse this answer Creative Commons License