What is the axis of symmetry of the graph of y=x^2-3x+9? Algebra Quadratic Equations and Functions Vertex Form of a Quadratic Equation 1 Answer Alberto M. May 8, 2015 x=32 the axis of symmetry of a parabola y=ax2+bx+c is given by x=−b2a (it's a vertical line), because −b2a is the x of vertex of the parabola, and you know the axis is vertical and passes through the vertex, so you're done: x=−(−32)⇒x=32 Answer link Related questions What is the Vertex Form of a Quadratic Equation? How do you find the vertex form of a quadratic equation? How do you graph quadratic equations written in vertex form? How do you write y+1=−2x2−x in the vertex form? How do you write the quadratic equation given a=−2 and the vertex (−5,0)? What is the quadratic equation containing (5, 2) and vertex (1, –2)? How do you find the vertex, x-intercept, y-intercept, and graph the equation y=−4x2+20x−24? How do you write y=9x2+3x−10 in vertex form? What is the vertex of y=−12(x−4)2−7? What is the vertex form of y=x2−6x+6? See all questions in Vertex Form of a Quadratic Equation Impact of this question 2925 views around the world You can reuse this answer Creative Commons License