Question #7f803

1 Answer
Jan 30, 2017

4sinxcosx-2sqrt3sinx+2cosx-sqrt3=04sinxcosx23sinx+2cosx3=0

=>2sinx(2cosx-sqrt3)+1(2cosx-sqrt3)=02sinx(2cosx3)+1(2cosx3)=0

=>(2cosx-sqrt3)(2sinx+1)=0(2cosx3)(2sinx+1)=0

So 2cosx-sqrt3=02cosx3=0
=>cosx=sqrt3/2=cos(pi/6)=cos(2pi-pi/6)=cos((11pi)/6)cosx=32=cos(π6)=cos(2ππ6)=cos(11π6)

Hence

=>x=pi/6 and (11pi)/6x=π6and11π6

Again

2sinx+1=02sinx+1=0

sinx=-1/2=-sin(pi/6)=sin(pi+pi/6)sinx=12=sin(π6)=sin(π+π6)

So =>x=(7pi)/6x=7π6

Again

sinx=-1/2=-sin(pi/6)=sin(2pi-pi/6)sinx=12=sin(π6)=sin(2ππ6)

=>x=(11pi)/6x=11π6

Hence solutions for 0<=x<=2pi0x2π

x = pi/6,(7pi)/6,(11pi)/6x=π6,7π6,11π6