Thursday, August 9, 2012

Solve for x in (0 ; 360) : 2 tan x - 1 = -tan (-x).

First, we'll re-write the right side term, based on the
fact that the tangent function is odd, so tg(-x)=-tgx.


The
equation will become:


2tanx-1=-(-tan
x)


We'll remove the
brackets:


2tan x-1 = tan
x


We'll subtract tan x both
sides:


2tan x-1 - tan x =
0


We'll combine lie terms:


tan
x - 1 = 0


We'll add 1:


tan x
=1


x=arctan1 + k*pi


But arctan
1= pi/4


x = pi/4


The tangent
is also positive in the 3rd quadrant, so x = pi + pi/4


x =
5pi/4


The  possible values of the angle are
{pi/4 ; 5pi/4}.

No comments:

Post a Comment

Calculate tan(x-y), if sin x=1/2 and sin y=1/3. 0

We'll write the formula of the tangent of difference of 2 angles. tan (x-y) = (tan x - tan y)/(1 + tan x*tan y) ...