How do I write quadratic functions and models?
7.2 Write Quadratic Functions and Models Example 1 Write a quadratic function in vertex form Write a quadratic function whose graph has a vertex ( ) and passes through the point (0, 5). Solution Vertex form Substitute for h and k. Use the point (___, ___) to find a. Substitute for x and y. Solve for a. A quadratic function for the parabola is __________________.
7.2 Write Quadratic Functions and Models Checkpoint. Complete the following exercise. 1.Write a quadratic function whose graph has vertex (2, 1) and passes through the point (0, 4).
7.2 Write Quadratic Functions and Models Example 2 Write a quadratic function in intercept form Write a quadratic function whose graph has x-intercepts and and passes through the point ( ). Solution Intercept form Substitute for p and q. Use the point to find a. Substitute for x and y. Solve for a. A quadratic function for the parabola is __________________.
7.2 Write Quadratic Functions and Models Checkpoint. Complete the following exercise. 2.Write a quadratic function whose graph has x-intercepts and 2, and passes through the point (3, 21).
7.2 Write Quadratic Functions and Models Example 3 Write a quadratic function in standard form Write a quadratic function in standard form for the parabola that passes through the points ( ), (0 ), and ( ). Substitute the coordinates of each point into y = ax 2 + bx + c to obtain a system of three equations. Substitute for x and y. Equation 1 Substitute for x and y. Equation 2 Substitute for x and y. Equation 3
7.2 Write Quadratic Functions and Models Example 3 Write a quadratic function in standard form Write a quadratic function in standard form for the parabola that passes through the points ( ), (0 ), and ( ). Rewrite the system as a system of two equations. Substitute for c. Revised Equation 1 Substitute for c. Revised Equation 3
7.2 Write Quadratic Functions and Models Example 3 Write a quadratic function in standard form Write a quadratic function in standard form for the parabola that passes through the points ( ), (0 ), and ( ). Solve the system consisting of revised Equations 1 and 3. Revised Equation 1 Revised Equation 3 Add equations. Solve for a. So, ___________=_____, which means b = ___. A quadratic function for the parabola is _____________________.
7.2 Write Quadratic Functions and Models Checkpoint. Complete the following exercise. 3.Write a quadratic function in standard form for the parabola that passes through the points and
7.2 Write Quadratic Functions and Models Pg. 266, 7.1 #1-11