Question

[Mỹ Uyên Nguyễn]

1. tan(2x + 10°) + cotx =0
2. tan(2x + 45°) . tan(180° - x/2) =1
3. cot(3x + 45°) - tan20° =0

Answer 1

[Trần Thị Như Trúc]

tan(2x+10^o)+cot(x)=0

<=> tan(2x+10^o)+tan(90^o-x)=0

<=>tan(x+100^o)*[1-tan(2x-10^o)*tan(90^o-x)]=0

*tan(x+100^o)=0 => x=....

*1-tan(2x-10^o)*tan(90^o-x)=0

<=> tan(2x-10^o)=tanx <=> x=....