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Exercise

Hello to everyone, i got this exercise to solve but i dont know how i can do it, can anyone help me out on that? Exercise requires you to implement an HTML page that uses a function in Javascript which approximates the value of pi. The proposed method requires calculating the integral 4 / (1 + x * x) in the interval from -1/2 to 1 / 2. The method divides the above space into n segments, where for each segment the integral is approximated by the expression (1 / n) * (4 / (1 + x * x)). The page has a form with an input where the user sets the value of n and a key that calls the function with the parameter n. The function of updating text on the web page with the value of the pi calculated.

10th Jan 2018, 7:49 PM
Giannis Tiniakos
Giannis Tiniakos - avatar
2 ответов
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From where did you got this exercise? Trying to resolve it, seems that computing integral (so even approximating) 4/(1+x*x) in the interval from -1/2 to 1/2 doesn't reach PI as limit ^^ Better way to compute (or approximate) integral of Math.sqrt(1-x*x) in the interval from -1 to 1, wich is half of unit circle area (PI/2): function getpi(n) { var p, m, x; if (n<1) p = ''; // compute and display PI only if n >= 1 else { p = 0; m = 1/n; x = -1+m/2; // approximate average of segment area with x at middle of each segment while (x<1) { p += m*Math.sqrt(1-x*x); x += m; } p *= 2; } document.getElementById('pi').innerHTML = p; } ... use it as: <input type="number" oninput="getpi(this.value);">
10th Jan 2018, 9:10 PM
visph
visph - avatar
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A friend asked me to post this and get the solution. Thanks :)
10th Jan 2018, 9:54 PM
Giannis Tiniakos
Giannis Tiniakos - avatar