Answer:
Explanation:
let tan 2x=y
y³-3y+2=0
y³-y-2y+2=0
y(y²-1)-2(y-1)=0
y(y+1)(y-1)-2(y-1)=0
(y-1)[y(y+1)-2]=0
(y-1)(y²+y-2)=0
(y-1)(y²+2y-y-2)=0
(y-1)[y(y+2)-1(y+2)]=0
(y-1)(y+2)(y-1)=0
y=1,1,-2
tan 2x=1=tanπ/4=tan (nπ+π/4)=tan π/4(n+1)
2x=π/4(n+1)
x=π/8(n+1)
where n is an integer.
tan 2x=-2