User guide

5.4 Finding intercepts and intersections
5.4.1 y-intercept and trace
We can use the calculator to approximate x and y intercepts. We begin with
the function y = 2x + 1. Both graphically and algebraically it is easy to see
that the graph crosses at (0, 1). We wish to use the calculator to check our
conclusion. Be sure that the graph is chosen as the active window. We know
that x = 0 for any y-intercept, we can use the Trace feature to find the value
of y. Choose Analysis from the menu bar then Trace.
Note that the cursor is blinking on a specific coordinate. The initial coor-
dinate may not be the same for every calculator. This would depend on
previous use of trace. From this screen, the calculator has a hidden feature
that allows the user to trace any (x, y) when x is specified. If we use our
keypad or keyboard to enter the value 0, we see a hidden evaluation feature.
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