My Math Forum Trig Interval Question

 Trigonometry Trigonometry Math Forum

 April 23rd, 2009, 10:30 AM #1 Newbie   Joined: Apr 2009 Posts: 3 Thanks: 0 Trig Interval Question I solved each problem, so if someone can check them I would appreciate it! 1. Solve the equation in the interval [0,2pi) tanxcosx-cosx=0 I found all solutions of the equation to be Cos: pi/2 +2npi ; 3pi/2 + 2npi The problem is both yield error when plugging into a calc so do I just exclude? n is any integer Tan: pi/4 +npi (this is just pi instead of 2pi because one period of tan is from (-pi/2, pi/2) If the question asks for the solutions in the interal [0,2pi) then the answers would just be pi/4? 2. Solve the equation in the interval [0,2pi) 2 cos^2x+sinx=1 For all solutions of the above I got 7pi/6 + 2npi; 11pi/6 + 2npi; pi/2 + 2npi So, for the interval [0,2pi] would it just be pi/2, 7pi/6, 11pi/6
 April 23rd, 2009, 10:42 AM #2 Newbie   Joined: Apr 2009 Posts: 3 Thanks: 0 Re: Trig Interval Question Here is some additional work for #1 and #2 1. tanxcosx-cosx=0 cosx(tanx-1)=0 cosx=0 thus x is pi/2 and 3pi/2 but when checked yields error tanx=1 @pi/4 2. 2cos^2x+sinx=1 2(1-sin^2x)+sinx-1=0 2-2sin^2x+sinx-1=0 -2sin^2x+sinx+1=0 -1(2sinx+1)(sinx-1)=0 2sinx+1=0 sin x=-1/2 @7pi/6 and 11pi/6 sinx-1=0 sin x =1 @pi/2

 Tags interval, question, trig

,

1/sinx cosx interal

Click on a term to search for related topics.
 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post lilyungn Advanced Statistics 0 June 20th, 2010 04:13 PM TsAmE Calculus 7 April 29th, 2010 11:23 AM 450081592 Calculus 2 November 15th, 2009 07:23 PM Kat-M Advanced Statistics 0 May 12th, 2009 10:26 AM sampimpinthug Algebra 2 June 14th, 2008 05:05 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top