Draggable exponential function: Difference between revisions
From JSXGraph Wiki
A WASSERMANN (talk | contribs) No edit summary |
A WASSERMANN (talk | contribs) No edit summary |
||
| (3 intermediate revisions by the same user not shown) | |||
| Line 7: | Line 7: | ||
<jsxgraph width="400" height="400" box="box1"> | <jsxgraph width="400" height="400" box="box1"> | ||
var board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 20, 5, - | var board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 20, 5, -2], axis:true}); | ||
var A = board.create('point', [1, Math.exp(1)]); | var A = board.create('point', [1, Math.exp(1)]); | ||
| Line 20: | Line 20: | ||
}], {fontSize: 16}); | }], {fontSize: 16}); | ||
</jsxgraph> | </jsxgraph> | ||
<html> | |||
<input type="button" onClick="alert('a = ' + (Math.log(A.Y()) / A.X()).toFixed(2))" value="Show value of a" /> | |||
</html> | |||
===The JavaScript code=== | ===The JavaScript code=== | ||
<source lang="javascript"> | <source lang="javascript"> | ||
var board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 20, 5, - | var board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 20, 5, -2], axis:true}); | ||
var A = board.create('point', [1, Math.exp(1)]); | var A = board.create('point', [1, Math.exp(1)]); | ||
| Line 36: | Line 38: | ||
return "a = " + (Math.log(A.Y()) / A.X()).toFixed(2); | return "a = " + (Math.log(A.Y()) / A.X()).toFixed(2); | ||
}], {fontSize: 16}); | }], {fontSize: 16}); | ||
</source> | |||
<source lang="html4strict"> | |||
<input type="button" onClick="alert('a = ' + (Math.log(A.Y()) / A.X()).toFixed(2))" value="Show value of a" /> | |||
</source> | </source> | ||
[[Category:Examples]] | [[Category:Examples]] | ||
[[Category:Calculus]] | [[Category:Calculus]] | ||
Latest revision as of 09:41, 16 February 2016
Plot the function
- [math]\displaystyle{ y = e^{ax} }[/math]
where the parameter [math]\displaystyle{ a }[/math] is determined by the Point [math]\displaystyle{ A=(x_A, y_A) }[/math].
That means,
- [math]\displaystyle{ a = log(y_A) / x_A }[/math]
The JavaScript code
var board = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 20, 5, -2], axis:true});
var A = board.create('point', [1, Math.exp(1)]);
var graph = board.create('functiongraph', [
function(x) {
var a = Math.log(A.Y()) / A.X();
return Math.exp(a * x);
}]);
var txt = board.create('text', [-3, 10, function () {
return "a = " + (Math.log(A.Y()) / A.X()).toFixed(2);
}], {fontSize: 16});
<input type="button" onClick="alert('a = ' + (Math.log(A.Y()) / A.X()).toFixed(2))" value="Show value of a" />
