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Kutzler & Kokol-Voljc: Introduction to D
ERIVE
5
31
not found a position at which the
y
-coordinate is zero, but you can say that the polynomial zero
must be between 1.6 and 1.62, probably being closer to 1.62. An obvious approach for getting
closer is magnification.
Zoom in using the Command Toolbar’s
Zoom in
button
(left picture), then move the
square closer to the rightmost zero.
Now you get
Cross: 1.62, 0.01688368
and
Cross: 1.61, -0.06817304
(or whatever numbers you
obtain) hence the polynomial zero is between 1.61 and 1.62.
Restore the original scale factors by zooming out with the
Zoom out
button
.
Find an approximation for the leftmost zero by moving the square to it.
The leftmost zero seems to be at exactly
x
=-2.
Document what you found so far by inserting appropriate text objects.
Switch to the algebra window. Resize the embedded plot: Select the image by clicking on it.
The image is surrounded by 8 black squares, which can be used to resize it. Move the mouse
pointer to the lower right corner until a double-headed arrow appears. Press and hold the
left mouse button. With the left mouse button held down, drag the pointer towards the
image center. When a suitable size is reached, release the mouse button.