randRange( 0, 2 )
1 / randRange( 2, 5 )
randRange( 1, 3 )
[ deskItem( 0 ), fruit( 0 ), "X" ][ INDEX ]
[
$._("# of %(unit)s", {unit: plural_form( UNIT )}),
$._("# of %(unit)s", {unit: plural_form( UNIT )}),
"X"
][ INDEX ]
[
$._("Cost of producing %(unit)s", {unit: plural_form( UNIT )}),
$._("Cost of producing %(unit)s", {unit: plural_form( UNIT )}),
"Y"
][ INDEX ]
$._("black arrow")
$._("green arrow")
How does Y change as X increases?
How does the cost of producing plural_form(UNIT) change as the number of plural_form(UNIT) increases?
init({
range: [[-3, 10], [-1, 10]],
scale: [30, 30]
});
grid( [10, 10], [10, 10], {
stroke: "#ccc"
});
style({
stroke: "#888",
strokeWidth: 2,
arrows: "->"
});
path( [ [-0.5, 0], [10, 0] ] );
path( [ [0, -0.5], [0, 10] ] );
style({
stroke: BLACK,
strokeWidth: 0.9,
arrows: "->"
});
label( [ 0, 9.2 ], "\\text{" + Y_AXIS_LABEL + "}", "right");
label( [ 8.5, 0], "\\text{" + X_AXIS_LABEL + "}", "below");
style({
stroke: BLUE,
strokeWidth: 2,
arrows: "->"
});
plot( function( x ) {
return ( M ) * x + B;
}, [0, 10]);
Increases
- Increases
- Decreases
- Stays the same
style({ fill: "", stroke: BLACK });
line( [ 4, 4 * M + B ], [ 7, 4 * M + B ] );
style({ stroke: GREEN });
line( [ 7, 4 * M + B ], [ 7, 7 * M + B ] );
Looking at the graph, we see that as x increases (\text{BLACK_ARROW}), y also increases (\green{\text{GREEN_ARROW}}).
We can say that the slope of the line is positive, or that the variables have a direct relationship.
Thus, as X increases, Y also increases.
Thus, as the number of plural_form(UNIT) increases, the price of plural_form(UNIT) also increases.
1 / randRange( 2, 5 ) * -1
randRange( 6, 8 )
$._("black arrow")
$._("red arrow")
Decreases
style({ fill: "", stroke: "#000000" });
line( [ 4, 4 * M + B ], [ 7, 4 * M + B ] );
style({ stroke: "#ff0000" });
line( [ 7, 4 * M + B ], [ 7, 7 * M + B ] );
Looking at the graph, we see that as x increases (\text{BLACK_ARROW}), y decreases (\red{\text{RED_ARROW}}).
We can say that the slope of the line is negative, or that the variables have an inverse relationship.
Thus, as X increases, Y decreases.
Thus, as the number of plural_form(UNIT) increases, the price of plural_form(UNIT) decreases.
0
randRange( 2, 8 )
Stays the same
Looking at the graph, we see that as x increases, there is no change in y.
We can say that the slope of the line is zero, or that the variables have no correlation.
Thus, as X increases, Y stays the same.
Thus, as the number of plural_form(UNIT) increases, the price of plural_form(UNIT) stays the same.