Find all of the exact solutions to the equation in the inter
Find all of the exact solutions to the equation in the interval [0,2 pi). 1 - sin(2x) = cos(4x)
Solution
0<=x<=2pi
0<=2x<=4pi
1-sin(2x)=cos(4x)
1-sin(2x)=cos(2*2x)
cos2A=1-2sin2A
1-sin(2x)=1-2sin2(2x)
2sin2(2x)-sin(2x)=0
sin(2x)[2sin(2x) -1]=0
sin2x=0 ,sin2x =1/2
sin2x=0 => 2x =0 ,pi,2pi,3pi
=>x=0,pi/2,pi,3pi/2
sin2x =1/2 =>2x=pi/6 ,5pi/6 ,13pi/6,17pi/6
x=pi/12,5pi/12,13pi/12,17pi/12
therefore x =0,pi/2,pi,3pi/2,pi/12,5pi/12,13pi/12,17pi/12 are solutions
