
Calculus Calculus Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 1st, 2009, 07:49 AM  #1 
Newbie Joined: Apr 2009 Posts: 28 Thanks: 0  INT[min(sinx, cosx)dx] from 0 to pi equals to ??
Dear Members, Any clue how to solve the following integrals? Thanks in advance!! 1. INT[min(sinx, cosx)dx] from 0 to pi equals to (A) 1 ? 2squrt(2) (B) 1 (C) 0 (D) 1 ? squrt(2). [color=#FF40FF]What’s the meaning of min(sinx, cosx), because no other criteria is given?[/color] 2. INT[sinxcosx/(x+1)^2 dx] from 0 to 4 == ? Tried to solve the above integral by 'Integration by Parts'. Since (x+1)^2 in the denominator it's power is increasing. 
May 1st, 2009, 05:38 PM  #2 
Global Moderator Joined: May 2007 Posts: 6,852 Thanks: 743  Re: INT[min(sinx, cosx)dx] from 0 to pi equals to ??
min(sinx,cosx) simply means take the smaller one for a given x. In the range 0 to pi, sin is smaller 0<x<pi/4, while cos is smaller pi/4 < x < pi. You just integrate each part separately and add the two integrals. As for the second integral, you can integrate by parts to go the other way, but it looks somewhat formidable. 
May 2nd, 2009, 02:32 AM  #3  
Newbie Joined: Apr 2009 Posts: 28 Thanks: 0  Re: INT[min(sinx, cosx)dx] from 0 to pi equals to ?? Quote:
Quote:
 

Tags 
cosxdx, equals, intminsinx 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Integrate sinx^n/(sinx^n+cosx^n)  szpaq234  Calculus  1  March 23rd, 2014 03:06 AM 
integration of Rational Functions of sinx and cosx  nephi39  Calculus  3  March 16th, 2012 02:15 AM 
Sinx+cosx=0  robyn  Algebra  3  July 14th, 2009 06:35 PM 
Integral of dx / (sinx + cosx) ^ 2  brittosd  Calculus  3  January 17th, 2009 02:39 PM 
Integral of sinx/cosx  nooblet  Calculus  1  January 17th, 2009 02:06 PM 