- chris cambré
Following applet illustrates two ways to use dynamic colors.
- The colors of the sign of a function f and the color of a Point P depent on a given condition.
- The colors of a slider s and a point C are calculated out of a variable value.
- sign of a function: The sign of a function
f(x)= ax + bdepends from the values of a and b.
- color of a point P: Point P colors green when it's on the graph of f and red if it's not.
- color of a slider: The color of slider s changes while moving the slider.
- color of a point C: The color of point P changes if you drag it along the segment l.
How do you do this?
- Sign of the function f: Create:
- a slider a from -4 to 4 with increment 0.5
- a slider b from-4 to 4 with increment 0.5
- a function
f(x) = a x + b- a number zero = -b/a - a number
c = Integral(f, -50, zero)- a number
d = Integral(f, zero, 50)Open the Properties of c and d, select the tab Advanced and define their dynamic colors so that a negative value will color red and a positive value will color green.
colors of c colors of d Red:
If(c < 0, 1, 0)
If(c > 0, 0.7, 0)
If(d < 0, 1, 0)
If(d > 0, 0.7, 0)
- Color of the point P: Create a point P, open its Properties and select the tab Advanced.
Define its colors so that P colors green when it's on the graph and green when it's not.
If(Distance(P, f) > 0, 1, 0)
If(Distance(P, f) ≟ 0, 0.7, 0)
- Color of the slider s: Create a slider from
0to 1 with increment 0.1. Define its color in the tab advanced of its Properties:
Moving the slider from 0 to 1 its color will change from blue to red.
- Color of the point C: Create:
- the Segment l between the points A and B:
l = Segment(A,B). - the Point C on the segment. - the Segment g between the points A and C:
g = Segment(A,C). Define its colors so that C will color from black to green while dragging it on the segment.