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 2nd-Trace, then 2-Zero The screen asks ‘Left bound?’. Use arrow keys to move the cursor to the left of one of the x-intercepts. 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 2nd-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 **Solutions, Zeros, Roots, and X-intercept all 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