|
Try the applet!
top
Sample submitted
solutions:
From: Mary, age 13
School: Taipei American School, Taipei,
Taiwan
1. What is the point of intersection
of the red and green lines?
(Please write as an ordered pair)
(20, 80)
2. Describe what the Zoom In button
does. Why does it make the red line disappear?
(Hint: Consider what points are on the red
line).
The zoom in button is used to scale down
the graph. The numbers on the x and y axis
become smaller, because you're looking more
closely at the scale. The red line disappears
because it intercepts the x- axis at -60,
and the y-axis at 60. Therefore, if you
zoom out so that all you can see of the
graph is points going up to 11 and negative
11, then obviously you would not be able
to see the red line.
3. Suppose you could add a fourth Zoom
button that would show the intersection
of the green line on the y-axis (the "y-intercept"),
but not show the red line at all. What would
your new button do?
(Hint: What would the new scale of the graph
be?)
The fourth zoom button would serve to zoom
in just to show the green line and where
it intercepts the x and y axis, but not
to the point where it would show the red
line. So, if you wanted to make a new graph
to only show where the green line intercepts
the x and y axis and the green line itself,
you would have several options. The graph
would have points going up to 20 and going
down 20. Like, the y-axis would have points
going up to 20, and points going down to
-20, so there are 40 points in between.
Bonus: Now change the equation for the
blue line. Experiment with different equations
until you can see your new line when the
graph is in the Zoomed In position. What
is the equation of your line?
y = 9/7 x + 10
From: Kai-Ling, age 13
School: Taipei American School, Taipei,
Taiwan
1. What is the point of intersection
of the red and green lines?
(Please write as an ordered pair)
(20, 80)
2. Describe what the Zoom In button does.
Why does it make the red line disappear?
(Hint: Consider what points are on the red
line).
The zoom in button shows the graph more
close up. Therefore the points only go up
to 11 and -11 from the origin which is (0,0).
The red line disappears because when the
graph was 'zoomed out' the red line crosses
the graph at 60 and -60. But when the graph
was 'zoomed in' the graph only showed up
to points 10 and -10. Thus, there is no
possible way that we could've seen the red
line.
3. Suppose you could add a fourth Zoom
button that would show the intersection
of the green line on the y-axis (the "y-intercept"),
but not show the red line at all. What would
your new button do?
(Hint: What would the new scale of the graph
be?)
The y-axis should reach up to 22 and -22.
The x-axis should reach up to 22 and a little
bit more and -22 and a little bit more.
There can also be more options. This button
should make the graph zoom in so we will
only be able to see the green line and its
y-intercept. Since the y-intercept is 20.
The scale increases and decreases by 2s.
Bonus: Now change the equation for the
blue line. Experiment with different equations
until you can see your new line when the
graph is in the Zoomed In position. What
is the equation of your line?
y = 9/7x + 10
top
|
