Originally Posted by
skystar sorry im rubbish i meant hyperbolic lines, ok so if i take what you said would i just substitute x=0 to get the intersection. i get confused as to how you get the circle from |z+2|=4
z=x+iy
| x+iy + 2|=4 group real and imaginary parts then mod
sqrt( ((x+2)^2) + (iy)^2)=4 Mr F says: And here's the mistake. $\displaystyle {\color{red}|a + ib| = \sqrt{a^2 + b^2}}$, NOT $\displaystyle {\color{red}\sqrt{a^2 + (ib)^2}}$.
and so on..
to get
((x+2)^2) - y^2 =16
where am i going wrong