arg(z+2)=(pi/6) i cannot get the answer in my book of y=(x+2)/(sqrt(3)) can anyone show me there steps?

I am just learning from Alan's post - Thank you Alan. 

$$arg(z+2)=\frac{\pi}{6}\\\\
arg(x+iy+2)=\frac{\pi}{6}\\\\
arg((x+2)+iy)=\frac{\pi}{6}\\\\
tan\left(\frac{\pi}{6}\right)=\frac{y}{x+2}\\\\
\frac{1}{\sqrt3}=\frac{y}{x+2}\\\\
y=\frac{x+2}{\sqrt3}\\\\$$

See the diagram at this address - I haven't work out how to insert pictures yet.

http://gyazo.com/7bb85148a5e4c5c1cb6bddbfc206bbea

Represent the complex number z by x + iy where x and y are real numbers. here, the arg function represents the angle between the line from the origin to the point {x+2, y} and the x-axis.  We are told this angle is pi/6. The tangent of this angle is just y/(x+2) so we know that:

tan(pi/6) = y/(x+2)

Now tan(pi/6) or tan(30°) is just 1/sqrt(3) so 1/sqrt(3) = y/(x+2)

Multiply both sides by x+2 to get y = (x+2)/sqrt(3)

$${\mathtt{tanofpiby6}} = \underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{tan}}{\left({\mathtt{30}}^\circ\right)} = {\mathtt{tanofpiby6}} = {\mathtt{0.577\: \!350\: \!269\: \!19}}$$

$${\mathtt{oneonsqrt3}} = {\frac{{\mathtt{1}}}{{\sqrt{{\mathtt{3}}}}}} = {\mathtt{oneonsqrt3}} = {\mathtt{0.577\: \!350\: \!269\: \!189\: \!625\: \!8}}$$