What is the vertex of y=4x−x2? Algebra Quadratic Equations and Functions Quadratic Functions and Their Graphs 1 Answer Mark D. Jun 23, 2018 (2,4) Explanation: −b2a gives the X coordinate of the vertex −42×−1=−4−2=2 Put x=2 into y=4x−x2 y=4×2−22 y=8−4.⇒y=4 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=x2−2x+3? How do you know if y=16−4x2 opens up or down? How do you find the x-coordinate of the vertex for the graph 4x2+16x+12=0? See all questions in Quadratic Functions and Their Graphs Impact of this question 1481 views around the world You can reuse this answer Creative Commons License