R Ringa New Member Joined May 14, 2008 Messages 26 Gender Male HSC 2008 Oct 1, 2008 #1 solve: tanx- 2sinx= 0 (for greater thenor equal to 0 and less then or equal to 2pie) Please help or just state what tanx is in terms of sinx and cosx as I forget.
solve: tanx- 2sinx= 0 (for greater thenor equal to 0 and less then or equal to 2pie) Please help or just state what tanx is in terms of sinx and cosx as I forget.
I Iruka Member Joined Jan 25, 2006 Messages 544 Gender Undisclosed HSC N/A Oct 1, 2008 #2 tan x = sin x / cos x, so if tan x - 2 sin x = 0 then sin x/ cos x - 2 sin x = 0 sin x(1/cos x - 2) = 0, so either sin x = 0 or cos x = 1/2. So x = 0, pi, 2pi or x = pi/3, 5pi/3.
tan x = sin x / cos x, so if tan x - 2 sin x = 0 then sin x/ cos x - 2 sin x = 0 sin x(1/cos x - 2) = 0, so either sin x = 0 or cos x = 1/2. So x = 0, pi, 2pi or x = pi/3, 5pi/3.
tommykins i am number -e^i*pi Joined Feb 18, 2007 Messages 5,730 Gender Male HSC 2008 Oct 1, 2008 #3 sinx/cosx - 2sinx = 0 sinx - 2sinxcosx = 0 sinx(1-2cosx) = 0 Solve from there.