Ch 6 1 Solve Quadratic Equations by Graphing

Ch. 6. 1: Solve Quadratic Equations by Graphing

Using the TI-Calculator • Solve for y, then press ‘y=‘ key. Enter the equation. • Press ‘Graph’ key (if can’t see graph, try hitting ‘Zoom’ and ‘Standard’) • The answer(s): – Where does the graph hit the x-axis? • Hit 2 nd-Trace, then 2 -Zero • The screen asks ‘Left bound? ’. Use arrow keys to move the cursor to the left of one of the xintercepts. Press ‘Enter’. • The screen asks ‘Right bound? ’. Use arrow keys to move the cursor to the right of that x-intercept. Press ‘Enter’. Then press ‘Enter’ again to ‘Guess’ the zero. • Repeat this process to find the other zero.

****You can have 2, 1, or 0 answers!**** • Vertex: minimum/maximum point of the graph – Press 2 nd-Trace, then 3 -(Minimum) for upward opening, 4 -(maximum) for downward opening – Again, follow previous slide’s directions for answering left bound and right bound questions. • Axis of Symmetry: Cuts Parabola in half – “x = “ x-value from vertex

Example: Parts to Know • Solution: x= -2, x = 1 • Vertex: (- 0. 5, 2. 25) • Axis of symmetry: x = - 0. 5 **Solutions, Zeros, Roots, and X-intercept all mean the same thing, find the value(s) of x!**

YOU TRY! Example: Parts to Know • Roots: • Vertex: • Axis of symmetry:

Example: Parts to Know • Roots: x= -3 • Vertex: (- 3, 0) • Axis of symmetry: x = - 3