Answer:
Step-by-step explanation:
divide by 25
2sin²x=2+cos x
sin²x+cos²x=1
sin²x=1-cos²x
2(1-cos²x)=2+cos x
2-2 cos²x=2+cos x
2cos²x+cos x=0
cos x(2 cos x+1)=0
cos x=0,
x=(2n+1)π/2
where n is an integer.
or
2cos x+1=0
cos x=-1/2=-cos π/3=cos (π-π/3),cos(π+π/3)=cos (2nπ+2π/3),cos (2nπ+4π/3)
x=(3n+1)2π/3,(3n+2)2π/3
where n is an integer.
