## Skip2mylou426 Group Title Find the integral of (cos^2(x))((cosxsin^2n+1)*(pi/2*sinx)+(sinxsin^2n+1)(pi/2*cosx)) from 0 to pi/2 one year ago one year ago

1. primeralph Group Title

Input it more clearly.

2. Skip2mylou426 Group Title

$\int\limits_{0}^{\pi/2}\cos ^{2}x(\cos x \sin ^{2n+1}(\frac{ \pi }{ 2 }sinx)+sinxsin ^{2n+1}(\frac{ \pi }{ 2 }cosx))dx$

3. primeralph Group Title

Go Wolfram.

4. Skip2mylou426 Group Title

I don't have the first clue on how to use that

5. primeralph Group Title
6. swissgirl Group Title

Wolfram sucks these days :(

7. primeralph Group Title

How?

8. swissgirl Group Title

Thats what happens with all these free awesome programs

9. primeralph Group Title

Well, I don't think it even has CAS. I don't use it though.

10. swissgirl Group Title

Well if you wanna see the steps then you gotta have membership

11. primeralph Group Title

Well, I'd expect them to do that.

12. swissgirl Group Title

Ummm this is an annoying function. @Skip2mylou426 what r u currently studying?

13. swissgirl Group Title

Wolfram was the best matrix calculator .........

14. primeralph Group Title

was?

15. primeralph Group Title

Think it's always been Matlab......

16. swissgirl Group Title

Welll ya Dont have matlab. I used to have mathematica but my comp broke down so dont have it no more :(

17. primeralph Group Title

@Skip2mylou426 I think the integral can't be evaluated easily because of the form sin(acos(b))

18. primeralph Group Title

@swissgirl Yeah, if you're into coding, you'll fancy Matlab.

19. swissgirl Group Title

I guess he went to the lou :)

20. Skip2mylou426 Group Title

I was trying to type that monstrosity into Wolfram. Epic fail. It didn't work at all.

21. doulikepiecauseidont Group Title
22. swissgirl Group Title

OMG IK THAT

23. swissgirl Group Title

It always happens to me

24. primeralph Group Title

There is no free CAS engine...........unless you can hack. Otherwise, get your pen and paper.

25. swissgirl Group Title

wait let me try wolframming it for u

26. Skip2mylou426 Group Title

A little rusty on the calculus. I haven't taken calc in 3 or 4 years unfortunately

27. swissgirl Group Title

What course are u taking now?

28. primeralph Group Title

@swissgirl No point. The integrand has the form of a switch variable 'n' which would leave the answer not numeric, but algebraic........which requires a CAS software.

29. Skip2mylou426 Group Title

It's called Problem Solving. It's a combination of every type of math course that could've possibly been taken.

30. swissgirl Group Title

FUNNNNNN :)

31. Skip2mylou426 Group Title

haha not quite. He only gives us 1 point per problem solved. All work is required and 500 points are needed to get an A. Class has one month left (halfway done) and I have 178 points right now. KILL ME.

32. primeralph Group Title

I don't see the point in putting that into an integral. The integrand can be simplified though....it just looks ugly.

33. primeralph Group Title

|dw:1372916840241:dw|

34. primeralph Group Title

|dw:1372917002693:dw|

35. primeralph Group Title

.........then you start using the identities......

36. swissgirl Group Title

Ohhhh cooollll Ya I shld have thought of cleaning it up by using identities :)

37. primeralph Group Title

Yeah, I'm sure you'd have figured it out eventually. It's just boring to look at.

38. Skip2mylou426 Group Title

so clean it up using identities, then plug in?

39. Skip2mylou426 Group Title

is that a square that cuts off at the end?

40. swissgirl Group Title

Yes it is

41. primeralph Group Title

|dw:1372917328459:dw|

42. Skip2mylou426 Group Title

thanks! think it'll be messy if I don't use identities first?

43. primeralph Group Title

Well, depending on how much math you know, yes and no. You might be able to notice the symmetry; and if you can't fiddle with it,

44. hobbs978 Group Title

45. hobbs978 Group Title

just thought i would point that out

46. primeralph Group Title

@hobbs978 Thanks. Yours too. No homo.

47. Skip2mylou426 Group Title

48. primeralph Group Title

You're welcome. Sorry I couldn't finish it; I'm kinda tired today.

49. Skip2mylou426 Group Title

It's ok, I wish I even remembered how to start it. I feel like a failure.

50. swissgirl Group Title

hahaha dont feel like one I took 2 semesters of stats earlier this yr and I cant remember pellet Yesterday I was looking at a question and was totally blank. I felt like the biggest failure

51. primeralph Group Title

It's funny how the system changes your words by itself. We know what you meant to type instead of "pellet"........

52. primeralph Group Title

@Skip2mylou426 http://www.sosmath.com/trig/Trig5/trig5/trig5.html

53. Skip2mylou426 Group Title

So after plugging everything in...I come up with a big fat zero...

54. swissgirl Group Title

hahahahaha :D Just smile

55. primeralph Group Title

Well, zero is an answer...in many cases.

56. Skip2mylou426 Group Title

I may have made a mistake. ugh. ok I'm going to attempt to draw this.. hold on

57. Skip2mylou426 Group Title

|dw:1372918536405:dw|

58. Skip2mylou426 Group Title

ok so the $\cos(0)^3$ is going to be equal to one and then I end up with..

59. primeralph Group Title

0

60. Skip2mylou426 Group Title

|dw:1372918796639:dw|

61. Skip2mylou426 Group Title

62. primeralph Group Title

Still 0

63. Skip2mylou426 Group Title

Ok that's what I originally had. Sorry, don't hate me

64. primeralph Group Title

No, I don't hate you. Stop bringing yourself down. Sure you're an awesome student.

65. Skip2mylou426 Group Title

I'm trying, I really am, but this class is insanely hard. The hardest class in our program is Modern Algebra (which I took last semester), and I thought that was easier than this. I'm at a loss. I don't know what to do.

66. swissgirl Group Title

Modern Algebra = Abstract Algebra?

67. Skip2mylou426 Group Title

Give or take. Our professor wrote the text for it

68. primeralph Group Title

69. swissgirl Group Title

Ok that is a really hard course.

70. swissgirl Group Title

71. primeralph Group Title

Well, it means you can't find the answers elsewhere......since the professor made them up.

72. swissgirl Group Title

hahahaha yaaaaaa My abstract algebra course was customized too

73. Skip2mylou426 Group Title

Almost our whole department is like that. The worst thing is that the majority of our professors are research-based and suck at teaching.

74. swissgirl Group Title

Like most profs out there who cant teach

75. primeralph Group Title

I learned a long time ago to never expect a professor to teach well. I just get the syllabus and do my thing.

76. Jhannybean Group Title

Exactly...

77. Jhannybean Group Title

Hmm.. @satellite73 perhaps?...

78. Skip2mylou426 Group Title

that's the issue with this class, he just gives you a bunch of problems with no material to work with

79. primeralph Group Title

Get "Engineering Math by KA Stroud" Then go to "Advanced Engineering Math" by anybody.......but Kreyszig........that'll be later because it doesn't explain easy.

80. primeralph Group Title

81. Skip2mylou426 Group Title

I probably lack the necessary skills to do that. Can't hurt to try though

82. swissgirl Group Title

Ya I only do free stuff. I got mathematica for free and all my textbooks in pdf formats

83. Jhannybean Group Title

84. primeralph Group Title

@Skip2mylou426 The first book explains quite well. I've used it for HS students, so it should be cool.

85. Skip2mylou426 Group Title

I'll have to check it out soon. Thanks again for your help, I think I'm going to go die now :)

86. primeralph Group Title

Stay safe.

87. experimentX Group Title

$\frac{2 (1)_{n-1}}{\pi \left( \frac 3 2\right)_{n-1} }$ http://mathworld.wolfram.com/PochhammerSymbol.html