
Calculus Calculus Math Forum 
 LinkBack  Thread Tools  Display Modes 
December 23rd, 2017, 05:28 AM  #1 
Newbie Joined: May 2017 From: uk Posts: 9 Thanks: 0  stationary points of a trig function
Hi, am I doing this right? Find the coordinates when the gradient of this function is equal to zero t = cos(θ) f '(t) = sin(θ) $\ \ \ \ \ \ \ \ $ = sin(θ) = 0 $\ \ \ \ $ θ = 0/sin $\ \ \ \ $ θ = 0 Plug 0 in to original equation t = cos(0) t = 1 Coordinates = 0,1 where gradient is zero. Last edited by skipjack; December 23rd, 2017 at 09:27 AM. 
December 23rd, 2017, 06:13 AM  #2 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,974 Thanks: 1156 Math Focus: Elementary mathematics and beyond 
$\sin\theta$ is periodic.

December 23rd, 2017, 09:30 AM  #3 
Global Moderator Joined: Dec 2006 Posts: 21,105 Thanks: 2324 
Having obtained sin(θ) = 0, one cannot divide by "sin". Instead, solve sin(θ) = 0 by using knowledge of the sin function. 

Tags 
function, points, stationary, trig 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Stationary Points  Tom2000  Calculus  26  October 18th, 2016 01:12 PM 
Stationary Points  ajrt3  Calculus  0  September 29th, 2014 01:10 PM 
Stationary points for DDE  ARTjoMS  Calculus  2  January 9th, 2013 12:59 PM 
stationary points  sahil112  Calculus  5  November 21st, 2012 12:51 PM 
Stationary points ..  wulfgarpro  Algebra  5  May 30th, 2010 03:14 AM 