Tg3x=0 ⇒3x=π/2+kπ,k∈Z;⇒x=π/6+kπ/3,k∈Z
<span>x²-3x-2=0
D=9+8=17
x</span>₁=(3+√17<span>)/2
x</span>₂=(3-√17<span>)/2
</span>(3+√17) (3-√17) 9-17 -8
x₁*x₂= ------------<span> * ----------- = --------- = --------- =-2
2 2 4 4
</span>
<C-x,<B-3x,<A-6x
x+3x+6x=180
10x=180
x=18-<C
18*3=54-<B
54*2=108-<A