sign up I login
 advanced
refer a friend - earn nickels!!

Ask & Discuss Questions with Community & Experts

Moderation Team
 90 chars left    advanced
Ask iit jee aieee pet cbse icse state board community Community Discussion Question: kindly reply
Forum Index -> Integral Calculus like the article? email it to a friend.  
Author Message
kane (2201)

Blazing goIITian

Olaaa!! Perrrfect answer. 393  [511 rates]

kane's Avatar

total posts: 869    
offline Offline

the value of the integral


(cos3x+cos5x)/(sin2x+sin4x)dx


there are numerous options besides I.I.T

<TABLE CELLSPACING="1" CELLPADDING="1" BORDER="0">
<TR><TD>


<DIV ALIGN="right">Glitter Graphics</DIV></TD></TR></TABLE>









    
sachinguptaiit (940)

Scorching goIITian

Olaaa!! Perrrfect answer. 166  [221 rates]

sachinguptaiit's Avatar

total posts: 203    
offline Offline

\int\frac{\cos x((1-\sin^2x)+(1-\sin^2x)^2)}{\sin^2x+\sin^4x}.dx\\\\\int\frac{(1-t^2)+(1-t^2)^2}{t^2+t^4}.dt\\\\\int\frac{t^4-3t^2+2}{t^2+t^4}.dt\\\\\int\frac{(t^4+t^2-4t^2+2)}{t^2+t^4}.dt\\\\\int dt-\int\frac{4t^2-2}{t^2(t^2+1)}.dt\\\\t+\int\frac{2}{t^2}.dt-\int\frac{6}{t^2+1}.dt\\\\\sin x -\frac{2}{\sin x}-6\tan^{-1}(\sin x)+ C


 


 


"Before you start some work, always ask yourself three questions - Why am I doing it, What the results might be and Will I be successful. Only when you think deeply and find satisfactory answers to these questions, go ahead."

Chanakya quotes (Indian politician, strategist and writer, 350 BC-275 BC)
 this reply: 19 points  (with Olaaa!! Perrrfect answer.   in 5 votes )   [?]
 
You have to be logged on to rate
  
kane (2201)

Blazing goIITian

Olaaa!! Perrrfect answer. 393  [511 rates]

kane's Avatar

total posts: 869    
offline Offline

thnxs a lot yaar.what a gr8 way to attempt this question


there are numerous options besides I.I.T

<TABLE CELLSPACING="1" CELLPADDING="1" BORDER="0">
<TR><TD>


<DIV ALIGN="right">Glitter Graphics</DIV></TD></TR></TABLE>









 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
ankitagg (314)

Scorching goIITian

Olaaa!! Perrrfect answer. 52  [79 rates]

ankitagg's Avatar

total posts: 244    
offline Offline

another way


get cos^3x and sin^2x common


then put sinx=t


cosxdx=dt


dx=dt/sinx


I=int. (1-t^2)(2-t^2)/t^2(1+t^2)


solve by partial frac.


ans.. sinx-2cosecx-6arctan(sinx)+C


 

 this reply: 5 points  (with Olaaa!! Perrrfect answer.   in 1 votes )   [?]
 
You have to be logged on to rate
  
venkat_tatolu (228)

Scorching goIITian

Olaaa!! Perrrfect answer. 30  [69 rates]

venkat_tatolu's Avatar

total posts: 244    
offline Offline
Integrand is the form of F(sinx,cosx)

1)If F(-Sinx,Cosx)=- F(Sinx,Cosx) then put cosx=t

2)If F(Sinx,-Cosx) =- F(Sinx,CosX) then put sinx=t.

3) If F(-sinx,-cosx)= F(sinx,cosx) then put tanx=t.

If 1) point failed then go to second point.If second point failed go to 3rd point.
Given problem is of second type.So put sinx=t.
If u remember above points then u can do any problem of above type.All the best.

***T.Venkat***
 this reply: 10 points  (with Olaaa!! Perrrfect answer.   in 2 votes )   [?]
 
You have to be logged on to rate
  
kane (2201)

Blazing goIITian

Olaaa!! Perrrfect answer. 393  [511 rates]

kane's Avatar

total posts: 869    
offline Offline

thnxs guys


there are numerous options besides I.I.T

<TABLE CELLSPACING="1" CELLPADDING="1" BORDER="0">
<TR><TD>


<DIV ALIGN="right">Glitter Graphics</DIV></TD></TR></TABLE>









 this reply: 0 points  (with Olaaa!! Perrrfect answer.   in 0 votes )   [?]
 
You have to be logged on to rate
  
 
Forum Index -> Integral Calculus
Go to:   

Top Offers for goIITians
Correspondence Courses
Brilliant Tutorials
Narayana Institute
Aakash Institute
Classroom/Crash Courses
Narayana - Kota , Delhi , Others
Brilliant Tutorials - Class , Crash
Aakash Institute - Medical , Engg
Online Test Series
Brilliant Tutorials
Narayana Institute
Aakash Institute
Mahesh Tutorials
AMITY      Sri Chaitanya