Attached integral calculator cannot solve

[toml_12953]

(11-15-2019 02:25 PM)Albert Chan Wrote:  

(11-15-2019 12:56 PM)Werner Wrote:  You just have to realise that

'∫(-2,2,(X^3*COS(X/2)+1/2)*√(4-X^2),X)'
= '∫(-2,2,X^3*COS(X/2)*√(4-X^2),X)' + '∫(-2,2,1/2*√(4-X^2),X)'

The first part is an odd function, so the integral is zero, and we are left with the easy second part.

To finish, second part = ½ area of half-circle (radius 2) = ½ (2 pi) = pi

(11-15-2019 02:04 PM)rprosperi Wrote:  With that answer, to access the WiFi network, do you suppose the 10th digit should be a 3 or a 4 ?

Wi-Fi password is the first 10 digits of the answer.
That implied round-toward-zero ⇒ password = 3141592653

Statisticians either round half to even or round half to odd:

Round half to even:
1.235 ==> 1.24
1.245 ==> 1.24
1.255 ==> 1.26
1.265 ==> 1.26

Round half to odd:
1.225 ==> 1.23
1.235 ==> 1.23
1.245 ==> 1.25
1.255 ==> 1.25

This way the rounding error is minimized in large populations of data.