Attached integral calculator cannot solve

11152019, 11:15 AM
Post: #1




Attached integral calculator cannot solve
Attached integral calculator cannot solve


11152019, 11:49 AM
Post: #2




RE: Attached integral calculator cannot solve
Have you tried numerical integration? No Prime here, but on the HP 50g we can do
'∫(2,2,(X^3*COS(X/2)+1/2)*√(4X^2),X)' →NUM 3.14159265359 

11152019, 12:05 PM
Post: #3




RE: Attached integral calculator cannot solve  
11152019, 12:56 PM
Post: #4




RE: Attached integral calculator cannot solve
You just have to realise that
'∫(2,2,(X^3*COS(X/2)+1/2)*√(4X^2),X)' = '∫(2,2,X^3*COS(X/2)*√(4X^2),X)' + '∫(2,2,1/2*√(4X^2),X)' The first part is an odd function, so the integral is zero, and we are left with the easy second part. Cheers, Werner 41CV†,42S,48GX,49G,DM42,DM41X,17BII,15CE,DM15L,12C,16CE 

11152019, 01:30 PM
Post: #5




RE: Attached integral calculator cannot solve  
11152019, 02:04 PM
Post: #6




RE: Attached integral calculator cannot solve
With that answer, to access the WiFi network, do you suppose the 10th digit should be a 3 or a 4 ? Setting a calculator to Fix 9 would lead most folks to use the 4, while the 10th digit actually is 3. Not sure what the network admin had in mind. Who would guess that numerical rounding rules would need to be specified for a WiFi password?
Bob Prosperi 

11152019, 02:20 PM
Post: #7




RE: Attached integral calculator cannot solve
Tom L Cui bono? 

11152019, 02:25 PM
Post: #8




RE: Attached integral calculator cannot solve
(11152019 12:56 PM)Werner Wrote: You just have to realise that To finish, second part = ½ area of halfcircle (radius 2) = ½ (2 pi) = pi (11152019 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 ? WiFi password is the first 10 digits of the answer. That implied roundtowardzero ⇒ password = 3141592653 

11152019, 02:42 PM
Post: #9




RE: Attached integral calculator cannot solve
(11152019 02:25 PM)Albert Chan Wrote:(11152019 12:56 PM)Werner Wrote: You just have to realise that 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. Tom L Cui bono? 

11152019, 07:02 PM
Post: #10




RE: Attached integral calculator cannot solve
Just for the fun of it, I tried the definite integral on my CASIO fix991EX, and it came up with the symbol for pi!


11162019, 03:13 AM
Post: #11




RE: Attached integral calculator cannot solve
(11152019 07:02 PM)lrdheat Wrote: Just for the fun of it, I tried the definite integral on my CASIO fix991EX, and it came up with the symbol for pi! Well... that's only 2 digits! No WiFi for you! Bob Prosperi 

11162019, 04:35 PM
Post: #12




RE: Attached integral calculator cannot solve
Seinfeld! Quotable for almost every aspect of life!


11162019, 04:57 PM
Post: #13




RE: Attached integral calculator cannot solve
Using Mathematica Home Edition 12.0, it took a little longer than usual with other equations but finally produced the Pi symbol. On my G2 it returned the equation unsolved, but when I hit Simplify, it returned Pi.


11162019, 07:35 PM
(This post was last modified: 11182019 02:14 PM by swagner53.)
Post: #14




RE: Attached integral calculator cannot solve
The Prime G1 had no problem coming up with the Pi symbol in CAS or 3.141592... in Home right away. Odd thing was both worked straight off using lowercase x, then when I tried later in Home received an "Error: Syntax Error" message until I changed to an uppercase X. Took 1.034_s in CAS and .588_s in Home.
BTW, also tried solving in Mathematica 12 Home Edition on an 8core, 64 GB RAM PC with 2 TB SSD. It took .656 seconds to return the Pi symbol, slightly longer than the HP Prime G1 in Home mode. 

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