trigo

3tan(x-π/12)=tan(x+π/12)
3(sin(x-π/12) / cos(x-π/12)) = sin(x+π/12) / cos(x+π/12)
3sin(x-π/12)cos(x+π/12) = sin(x+π/12)cos(x-π/12)
3sin(x-π/12)cos(x+π/12) - sin(x+π/12)cos(x-π/12) = 0

Let a=x-π/12, b=x+π/12
--> a+b=(x-π/12)+(x+π/12) = 2x
--> a-b=(x-π/12)-(x+π/12) = -π/6

3sinacosb - cosasinb = 0
3sinacosb - 3cosasinb + 2cosasinb = 0
3sin(a-b) + 2cosasinb = 0

2cosasinb -->
= cosasinb + sinacosb + cosasinb - sinacosb
= cosasinb + sinacosb - sinacosb + cosasinb
= cosasinb + sinacosb - (sinacosb - cosasinb)
= sin(a+b) - sin(a-b)
-->
3sin(a-b) + sin(a+b) - sin(a-b) = 0
3sin(-π/6) + sin(2x) - sin(-π/6) = 0
3(-0.5) + sin2x + 0.5 = 0
sin2x = 1
2x = π/2
x = π/4 or π/4 + π = 5π/4