Items tagged with integration

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There seems to be a bug with improper integration:

integrate(cos(t)*exp(-x*t),t=-infinity..infinity)

gives

0

Substituting any number for x, or assuming x >= 0  (or x<=0) does give the correct result,

The problem also persists when assuming x>-1 (or x>-Maple_floats(MIN_FLOAT))

hi every one, i want to plot an indefinite integral  , it is some what complex and maple can not compute the answer, ( but numeric integration can be computed) , but we want to plot the output, what should we do ? tnx for help in advance

corrected.mw

I would like to have my calculus results in its simplified form; below are some of the scenarios that can explain this.

 

 

As you can see the results are much simplified and in reduced form compared to what Maple gives. This has been tested for all integrals with roots and integrals with trigonometry functions. Is there any workaround in Maple that I would use to get it like the textbook result.

Thanks

 

I'm trying to normalize a function, which is pretty standard in QM. But I don't understand why I'm getting such a crazy answer. I know it is possible to normalize this function (because I was asked to do so), it's just not working.

harmoscforbidden_fail.mw

I'm trying to obtain integral of Planck radiation law in Maple:

with this command:

f := (2*h*(c)^(2))/((x)^(5))*(1)/(exp((h*c)/(x*k*T))-1);
int(f,x=0..infinity);

but I get some terrible limit that cannot be solved instead of the correct result:

How to obtain correct integral?

planck.mw

i want to know the area under a diagram plotted by pdsolve, how can i do that? for example in below , what is the area under p1 diagram?


 

restart:k:=5;

5

(1)

EQ:=diff(u(x,t),t)=k*diff(u(x,t),x$2);

diff(u(x, t), t) = 5*(diff(diff(u(x, t), x), x))

(2)

ibc:=u(0,t)=0,u(1,t)=0, u(x,0) = x;

u(0, t) = 0, u(1, t) = 0, u(x, 0) = x

(3)

sol:=pdsolve({EQ},{ibc},numeric);

_m2021168030176

(4)

p1:=sol:-plot(u,x=0.5,t=0...10,style = line,color = "Blue",legend = "heat Plot",axes=boxed);

 

M:=op(1,op(1,p1));

M := Array(1..201, 1..2, {(1, 1) = .0, (1, 2) = .5, (2, 1) = 0.5e-1, (2, 2) = .2702110502740721, (3, 1) = .1, (3, 2) = -0.176887059080428e-1, (4, 1) = .15, (4, 2) = -0.6515347962762406e-2, (5, 1) = .2, (5, 2) = 0.74109221595503715e-2, (6, 1) = .25, (6, 2) = -0.6178984348254404e-2, (7, 1) = .3, (7, 2) = 0.49645329554988925e-2, (8, 1) = .35, (8, 2) = -0.3948699801548904e-2, (9, 1) = .4, (9, 2) = 0.31161325326115076e-2, (10, 1) = .45, (10, 2) = -0.24369292293079273e-2, (11, 1) = .5, (11, 2) = 0.18845070914387395e-2, (12, 1) = .55, (12, 2) = -0.14366378752131666e-2, (13, 1) = .6, (13, 2) = 0.10748767238662861e-2, (14, 1) = .65, (14, 2) = -0.7839388660633711e-3, (15, 1) = .7, (15, 2) = 0.5511660027174686e-3, (16, 1) = .75, (16, 2) = -0.3660810752890637e-3, (17, 1) = .8, (17, 2) = 0.22001797006812284e-3, (18, 1) = .85, (18, 2) = -0.10581369353881973e-3, (19, 1) = .9, (19, 2) = 0.1755251750102873e-4, (20, 1) = .95, (20, 2) = 0.4964665498398858e-4, (21, 1) = 1.0, (21, 2) = -0.9980698165105276e-4, (22, 1) = 1.05, (22, 2) = 0.1362404856962589e-3, (23, 1) = 1.1, (23, 2) = -0.16167000912668705e-3, (24, 1) = 1.15, (24, 2) = 0.17833050358069153e-3, (25, 1) = 1.2, (25, 2) = -0.18805314257842951e-3, (26, 1) = 1.25, (26, 2) = 0.19233515285281392e-3, (27, 1) = 1.3, (27, 2) = -0.19239777469550633e-3, (28, 1) = 1.35, (28, 2) = 0.18923435555607597e-3, (29, 1) = 1.4, (29, 2) = -0.18365024366673088e-3, (30, 1) = 1.45, (30, 2) = 0.17629586775928352e-3, (31, 1) = 1.5, (31, 2) = -0.16769415545232156e-3, (32, 1) = 1.55, (32, 2) = 0.15826324867687376e-3, (33, 1) = 1.6, (33, 2) = -0.1483353129733858e-3, (34, 1) = 1.65, (34, 2) = 0.1381721031382132e-3, (35, 1) = 1.7, (35, 2) = -0.12797783595325005e-3, (36, 1) = 1.75, (36, 2) = 0.11790982779578369e-3, (37, 1) = 1.8, (37, 2) = -0.10808727763435372e-3, (38, 1) = 1.85, (38, 2) = 0.9859851163881829e-4, (39, 1) = 1.9, (39, 2) = -0.8950695218043435e-4, (40, 1) = 1.95, (40, 2) = 0.8085602954949057e-4, (41, 1) = 2.0, (41, 2) = -0.7267321775920382e-4, (42, 1) = 2.05, (42, 2) = 0.6497334507523223e-4, (43, 1) = 2.1, (43, 2) = -0.5776130436199765e-4, (44, 1) = 2.15, (44, 2) = 0.5103426709812118e-4, (45, 1) = 2.2, (45, 2) = -0.4478348725852213e-4, (46, 1) = 2.25, (46, 2) = 0.3899576658643508e-4, (47, 1) = 2.3, (47, 2) = -0.336546405833609e-4, (48, 1) = 2.35, (48, 2) = 0.28741334410836633e-4, (49, 1) = 2.4, (49, 2) = -0.2423552947809686e-4, (50, 1) = 2.45, (50, 2) = 0.20115974495047912e-4, (51, 1) = 2.5, (51, 2) = -0.16360968960468515e-4, (52, 1) = 2.55, (52, 2) = 0.12948742231058999e-4, (53, 1) = 2.6, (53, 2) = -0.985774731176686e-5, (54, 1) = 2.65, (54, 2) = 0.706688518346671e-5, (55, 1) = 2.7, (55, 2) = -0.4555672725651303e-5, (56, 1) = 2.75, (56, 2) = 0.23043650036730538e-5, (57, 1) = 2.8, (57, 2) = -0.29404079279315267e-6, (58, 1) = 2.85, (58, 2) = -0.14933413612624144e-5, (59, 1) = 2.9, (59, 2) = 0.30749105483557417e-5, (60, 1) = 2.95, (60, 2) = -0.4466869448461453e-5, (61, 1) = 3.0, (61, 2) = 0.5684494809229467e-5, (62, 1) = 3.05, (62, 2) = -0.67421491593684444e-5, (63, 1) = 3.1, (63, 2) = 0.765330108066053e-5, (64, 1) = 3.15, (64, 2) = -0.8430551865031369e-5, (65, 1) = 3.2, (65, 2) = 0.9085666798487518e-5, (66, 1) = 3.25, (66, 2) = -0.9629609655930039e-5, (67, 1) = 3.3, (67, 2) = 0.10072579272402201e-4, (68, 1) = 3.35, (68, 2) = -0.1042404728762369e-4, (69, 1) = 3.4, (69, 2) = 0.1069279635035891e-4, (70, 1) = 3.45, (70, 2) = -0.10886958224421352e-4, (71, 1) = 3.5, (71, 2) = 0.11014051364892259e-4, (72, 1) = 3.55, (72, 2) = -0.11081017636391213e-4, (73, 1) = 3.6, (73, 2) = 0.11094257929051255e-4, (74, 1) = 3.65, (74, 2) = -0.11059666495657345e-4, (75, 1) = 3.7, (75, 2) = 0.109826638880031e-4, (76, 1) = 3.75, (76, 2) = -0.10868228414258878e-4, (77, 1) = 3.8, (77, 2) = 0.10720926073958364e-4, (78, 1) = 3.85, (78, 2) = -0.1054493895470911e-4, (79, 1) = 3.9, (79, 2) = 0.1034409209623252e-4, (80, 1) = 3.95, (80, 2) = -0.10121878843963985e-4, (81, 1) = 4.0, (81, 2) = 0.9881484727059153e-5, (82, 1) = 4.05, (82, 2) = -0.9625809905064345e-5, (83, 1) = 4.1, (83, 2) = 0.9357490234275213e-5, (84, 1) = 4.15, (84, 2) = -0.9078917009490728e-5, (85, 1) = 4.2, (85, 2) = 0.87922554398473e-5, (86, 1) = 4.25, (86, 2) = -0.8499461919063325e-5, (87, 1) = 4.3, (87, 2) = 0.8202300151001906e-5, (88, 1) = 4.35, (88, 2) = -0.7902356191213331e-5, (89, 1) = 4.4, (89, 2) = 0.7601052464222056e-5, (90, 1) = 4.45, (90, 2) = -0.72996608149495766e-5, (91, 1) = 4.5, (91, 2) = 0.699931465092186e-5, (92, 1) = 4.55, (92, 2) = -0.6701020229904285e-5, (93, 1) = 4.6, (93, 2) = 0.6405667145430395e-5, (94, 1) = 4.65, (94, 2) = -0.6114038060383664e-5, (95, 1) = 4.7, (95, 2) = 0.5826817736440689e-5, (96, 1) = 4.75, (96, 2) = -0.5544601404792595e-5, (97, 1) = 4.8, (97, 2) = 0.52679025211894145e-5, (98, 1) = 4.85, (98, 2) = -0.4997159946020307e-5, (99, 1) = 4.9, (99, 2) = 0.47327445878452e-5, (100, 1) = 4.95, (100, 2) = -0.4474965546586055e-5, (101, 1) = 5.0, (101, 2) = 0.4224075790442743e-5, (102, 1) = 5.05, (102, 2) = -0.3980277398539528e-5, (103, 1) = 5.1, (103, 2) = 0.3743726399348483e-5, (104, 1) = 5.15, (104, 2) = -0.35145372330544755e-5, (105, 1) = 5.2, (105, 2) = 0.3292786864253045e-5, (106, 1) = 5.25, (106, 2) = -0.3078518569671755e-5, (107, 1) = 5.3, (107, 2) = 0.28717454240173786e-5, (108, 1) = 5.35, (108, 2) = -0.2672453505531053e-5, (109, 1) = 5.4, (109, 2) = 0.2480604841418905e-5, (110, 1) = 5.45, (110, 2) = -0.22961401119743008e-5, (111, 1) = 5.5, (111, 2) = 0.21189811309571416e-5, (112, 1) = 5.55, (112, 2) = -0.19490331186010634e-5, (113, 1) = 5.6, (113, 2) = 0.17861867825155937e-5, (114, 1) = 5.65, (114, 2) = -0.16303202207033257e-5, (115, 1) = 5.7, (115, 2) = 0.14813006599365237e-5, (116, 1) = 5.75, (116, 2) = -0.13389860418240196e-5, (117, 1) = 5.8, (117, 2) = 0.12032264680435905e-5, (118, 1) = 5.85, (118, 2) = -0.10738655154134225e-5, (119, 1) = 5.9, (119, 2) = 0.9507414307327055e-6, (120, 1) = 5.95, (120, 2) = -0.8336882146176523e-6, (121, 1) = 6.0, (121, 2) = 0.7225366029120385e-6, (122, 1) = 6.05, (122, 2) = -0.6171149536407717e-6, (123, 1) = 6.1, (123, 2) = 0.5172500469062582e-6, (124, 1) = 6.15, (124, 2) = -0.422767804599377e-6, (125, 1) = 6.2, (125, 2) = 0.3334939363034557e-6, (126, 1) = 6.25, (126, 2) = -0.24925451730719557e-6, (127, 1) = 6.3, (127, 2) = 0.1698765042164462e-6, (128, 1) = 6.35, (128, 2) = -0.9518819325289293e-7, (129, 1) = 6.4, (129, 2) = 0.25019625957658297e-7, (130, 1) = 6.45, (130, 2) = 0.4079705332935711e-7, (131, 1) = 6.5, (131, 2) = -0.10242728416703212e-6, (132, 1) = 6.55, (132, 2) = 0.16003381713738053e-6, (133, 1) = 6.6, (133, 2) = -0.21377647792892648e-6, (134, 1) = 6.65, (134, 2) = 0.2638119651684455e-6, (135, 1) = 6.7, (135, 2) = -0.31029367903289395e-6, (136, 1) = 6.75, (136, 2) = 0.3533715778983202e-6, (137, 1) = 6.8, (137, 2) = -0.3931920604894687e-6, (138, 1) = 6.85, (138, 2) = 0.4298978711906126e-6, (139, 1) = 6.9, (139, 2) = -0.4636280263535863e-6, (140, 1) = 6.95, (140, 2) = 0.494517759612214e-6, (141, 1) = 7.0, (141, 2) = -0.5226984843620009e-6, (142, 1) = 7.05, (142, 2) = 0.5482977717131691e-6, (143, 1) = 7.1, (143, 2) = -0.5714393423533197e-6, (144, 1) = 7.15, (144, 2) = 0.5922430708876365e-6, (145, 1) = 7.2, (145, 2) = -0.610825001331253e-6, (146, 1) = 7.25, (146, 2) = 0.6272973725430698e-6, (147, 1) = 7.3, (147, 2) = -0.641768652482882e-6, (148, 1) = 7.35, (148, 2) = 0.6543435802710991e-6, (149, 1) = 7.4, (149, 2) = -0.6651232151103739e-6, (150, 1) = 7.45, (150, 2) = 0.6742049912106031e-6, (151, 1) = 7.5, (151, 2) = -0.6816827779311618e-6, (152, 1) = 7.55, (152, 2) = 0.6876469444194619e-6, (153, 1) = 7.6, (153, 2) = -0.6921844280904861e-6, (154, 1) = 7.65, (154, 2) = 0.6953788063481056e-6, (155, 1) = 7.7, (155, 2) = -0.6973103710014924e-6, (156, 1) = 7.75, (156, 2) = 0.6980562048815929e-6, (157, 1) = 7.8, (157, 2) = -0.6976902602061175e-6, (158, 1) = 7.85, (158, 2) = 0.6962834382846133e-6, (159, 1) = 7.9, (159, 2) = -0.6939036701932665e-6, (160, 1) = 7.95, (160, 2) = 0.690615998086224e-6, (161, 1) = 8.0, (161, 2) = -0.6864826568410622e-6, (162, 1) = 8.05, (162, 2) = 0.6815631557688252e-6, (163, 1) = 8.1, (163, 2) = -0.6759143601450263e-6, (164, 1) = 8.15, (164, 2) = 0.669590572344911e-6, (165, 1) = 8.2, (165, 2) = -0.6626436123890619e-6, (166, 1) = 8.25, (166, 2) = 0.6551228977290213e-6, (167, 1) = 8.3, (167, 2) = -0.647075522119317e-6, (168, 1) = 8.35, (168, 2) = 0.6385463334437125e-6, (169, 1) = 8.4, (169, 2) = -0.629578010378859e-6, (170, 1) = 8.45, (170, 2) = 0.6202111377936157e-6, (171, 1) = 8.5, (171, 2) = -0.6104842807971703e-6, (172, 1) = 8.55, (172, 2) = 0.6004340573606388e-6, (173, 1) = 8.6, (173, 2) = -0.5900952094508935e-6, (174, 1) = 8.65, (174, 2) = 0.5795006726227363e-6, (175, 1) = 8.7, (175, 2) = -0.5686816440282655e-6, (176, 1) = 8.75, (176, 2) = 0.5576676488088356e-6, (177, 1) = 8.8, (177, 2) = -0.5464866048451384e-6, (178, 1) = 8.85, (178, 2) = 0.5351648858455677e-6, (179, 1) = 8.9, (179, 2) = -0.5237273827621483e-6, (180, 1) = 8.95, (180, 2) = 0.5121975635274654e-6, (181, 1) = 9.0, (181, 2) = -0.5005975311119593e-6, (182, 1) = 9.05, (182, 2) = 0.488948079906314e-6, (183, 1) = 9.1, (183, 2) = -0.4772687504359755e-6, (184, 1) = 9.15, (184, 2) = 0.46557788242095225e-6, (185, 1) = 9.2, (185, 2) = -0.45389266619653036e-6, (186, 1) = 9.25, (186, 2) = 0.4422291925122823e-6, (187, 1) = 9.3, (187, 2) = -0.43060250073186364e-6, (188, 1) = 9.35, (188, 2) = 0.4190266254556287e-6, (189, 1) = 9.4, (189, 2) = -0.4075146415927183e-6, (190, 1) = 9.45, (190, 2) = 0.39607870790862633e-6, (191, 1) = 9.5, (191, 2) = -0.38473010907775763e-6, (192, 1) = 9.55, (192, 2) = 0.37347929627010353e-6, (193, 1) = 9.6, (193, 2) = -0.362335926303425e-6, (194, 1) = 9.65, (194, 2) = 0.35130889939221703e-6, (195, 1) = 9.7, (195, 2) = -0.34040639552618525e-6, (196, 1) = 9.75, (196, 2) = 0.3296359095107469e-6, (197, 1) = 9.8, (197, 2) = -0.3190042847032402e-6, (198, 1) = 9.85, (198, 2) = 0.30851774547799635e-6, (199, 1) = 9.9, (199, 2) = -0.29818192845446557e-6, (200, 1) = 9.95, (200, 2) = 0.2880019125209349e-6, (201, 1) = 10.0, (201, 2) = -0.2779822476886622e-6}, datatype = float[8], order = C_order)

(5)

 

 

 

 


 

Download heat_equation_(2).mw

I am trying to evaluate the following triple integral but it takes much time so i kill the job.


 

restart; R := 5; KK := proc (theta) options operator, arrow; evalf(int(int(int(1/(R*sin(theta)^2+(R*cos(theta)+Z)^2+(2*R*k.sin(theta))*cos(p))^2, p = 0 .. 2*Pi), Z = 0 .. 60), k = 1 .. 10, numeric)) end proc; evalf(KK((1/6)*Pi))

Warning,  computation interrupted

 

``


 

Download int_maple_prime2.mw

I am trying to evaluate the following function for which I am getting a result 0. I just need to make sure the approach as well as result is correct or not. Thanks in advance. 
 

restart; Digits := 20; r := 5; Z := 0; KK := proc (phi) options operator, arrow; evalf(int(sin(phi)*sin(-arctan((p*cos(phi)+Z)/sqrt(p^2*sin(phi)^2+r^2)))*hypergeom([5/2, 3/2], [5/2], sin(-arctan((p*cos(phi)+Z)/sqrt(p^2*sin(phi)^2+r^2)))^2)/(p^2*sin(phi)^2+r)^2, p = -1 .. 1, numeric)) end proc; evalf(KK((1/6)*Pi))

0.

(1)

``


 

Download int(maple_prime).mw

I just quickly checked Nasser Abassi 12000.org to see if he's updated it for Maple 2017.  In some areas he has.  I thought I would check one of the integrals that failed for Maple in his tests.  In the Computer Algegbra independent integration tests Maple failed to solve 11.68% of the 3407 integrals in his test while Mathematica only failed 0.88%.  For Maple that seemed quite high, so it is perhaps his method of solving for Maple and perhaps he's more adept with Mathematica. 

Here is one of the failed integrals and the single line code he used to solve it.

int((5*x^2+3*(x+exp(x))^(1/3)+exp(x)*(2*x^2+3*x))/x/(x+exp(x))^(1/3),x) # of course because it failed it just spits back the integral.

Can maple solve it?

The answer is supposed to be

I recently encontered a very strange result.

Lets define the procedure:

Fg := proc(x0,y0)
if (x0>=0)and(x0<=3) and (y0<=x0+2) and (y0>=x0-1) and (y0>=0) and (y0 <=3) then
return y0*(3-y0)*x0*(3-x0)*(x0+2-y0)*(y0-x0+1);
else
return 0;
end if:
end proc:

The plot looks like needed:

plot3d('Fg'(x,y), x=0..3, y=0..3);

But integration returns weird result:

evalf(Int('Fg'(x,y), [x=0..1, y=0..2.1]));

7.888753239

evalf(Int('Fg'(x,y), [x=0..1, y=0..2.2]));

Error, (in evalf/int) when calling 'Fg'. Received: 'cannot determine if this expression is true or false: 0 <= x and x <= 3 and y <= x+2 and x-1 <= y and 0 <= y and y <= 3'

Fix_integrations.mw

Could you any one help me to fix this application and find the result for integrations?

 

Many thank,

Hi, I know the commands for when both curves/functions are y=....., but not when one of them is y=... and the other is a straight line going through the x-axis. I would like to be able to find the points of intersection in decimals, to plot them together such that I can see the points of intersection and finally I need to find he area enclosed between the two. Would appreciate your help.

Hello all,

So far I have been unable to find this question anywhere, but I apologize if it is a duplicate. I'm trying to evaluate the integral of sechq(x), where q is a positive integer. Mathematica is able to tell me the result (a hypergeometric function), but for some reason, Maple seems not to be able to compute this integral, it just gives me back the integral. A higher info-level on the 'int' function reveals a line that says 'Risch d.e. has no solution', but I'm not sure if that has anything to do with my problem. Any suggestions or tips on how to get an answer out of Maple would be greatly appreciated!

I want to calculate the following integral numerically with required precision.

First, the functions are defined:

G1:=-0.9445379894;
f:= (x) -> 0.9/abs(x-0.4)^(1/3)+0.1/abs(x-0.6)^(1/2);
U1 := unapply(-exp(-x)*(evalf(Int(f(t)*exp(t), t = 0 .. x))+G1)/2-exp(x)*(evalf(Int(f(t)*exp(-t), t = 0 .. x))+G1)/2, x);
U:= unapply(-exp(x)/2*(evalf(Int(f(t)*exp(-t),t=0..x))+G1)+exp(-x)/2*(evalf(Int(f(t)*exp(t),t=0..x))+G1), x);

Next, I calculate the integral in numerical form:

evalf(Int(U1(x)^2+U(x)^2-2*f(x)*U(x), x=0..1, digits=4, method = _Gquad));

If I specify digits=4, Maple return the answer -0.4291

If I use digits=5 or larger, Maple return someting like this

Is it possible to increase precision of calculation?


 

 

Hey guyz, I am in trouble with calculation attached integral. it is a simple function but a bit long. I can't solve it with maple, Do U have any idea?

 

 

intg.mw

 

 

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