How do you find the exact value of #sqrt3-sinx=sinx+sqrt12# in the interval #0<=x<360#?

2 Answers
Nov 25, 2016

#" "x=-pi/3" " or" "x=(4pi)/3#

Explanation:

#" "#
Solving the equation by transferring the knowns to one side and
#" "#
unknown to the second side.
#" "#
In this equation we will use the following identities:
#" "#
#color(blue)(sin(-alpha)= - sinalpha)#
#" "#
#color(red)(sin(pi+alpha)=-sinalpha)#
#" "#
#-sinx - sinx =-sqrt3+sqrt12#
#" "#
#rArr-2sinx=-sqrt3+sqrt(2^2xx3)#
#" "#
#rArr-2sinx = -sqrt3+2sqrt3#
#" "#
#rArr-2sinx = +sqrt3#
#" "#
#rArrsinx = -sqrt3/2#
#" "#
#rArrsinx = - sin(pi/3)#
#" "#
#sin<0" "# therefore the angle #in #Quadrant 3 or 4

#rArrsinx = color(blue)(sin(-pi/3))" " Or " "sinx = color(red)sin(pi+pi/3)#
#" "#
Hence ,#" "x=-pi/3" " or" "x=(4pi)/3#

Nov 25, 2016

#240^@ and 300^@#

Explanation:

sqrt3 - sin x = sin x + sqrt12
After transposing:
# - 2sin x = sqrt12 - sqrt3 = 2sqrt3 - sqrt3 = sqrt3#
#sin x = - sqrt3/2#
Trig table of special arcs and unit circle give 2 solutions:
#sin x = - sqrt3/2# -->
arc #x = - pi/3 = - 60^@# and arc #x = - (2pi)/3 = - 120^@#
The arcs #240^@# and #300^@# are co-terminal to the arcs # - 120^@ # and #- 60^@#

Answers for (0, 360)
#240^@ and 300^@#