6.3 Graph Quadratics Using the x-Intercepts

To find the y-coordinate of the vertex, substitute x 4 into the equation of the parabola. y xx2 8 7 ( 4)2 8( 4) 7 16 32 7 9 The coordinates of the vertex are ( 4, 9). b) Factor and solve the corresponding quadratic equation. y x2x2 6 0 x2 2 x 6 0 x2 2 3x 4x 6 0 x(2 3) 2(2x 3) 0 (2x 3)(x 2) 2x 3 0orx 2 0 x or x 2 The x-intercepts are and 2. Now, find the x-coordinate of the vertex. ................
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