So once you click on latex and you have [ tex ] & [ /tex ] what do you do?
So, for example, my post (excluding the tex codes) was:
\begin{align*} \frac{1}{z} + \frac{1}{\bar{z}} &= \frac{1}{z} \times \frac{\bar{z}}{\bar{z}} + \frac{1}{\bar{z}} \times \frac{z}{z} \\ &= \frac{\bar{z} + z}{z\bar{z}} \\ &= \frac{\bar{z} + z}{|z|^2} \text{ as } z\bar{z} = |z|^2 \\ &= \frac{2\Re{(z)}}{|z|^2} \text{ as } z + \bar{z} = 2 \times \Re{(z)} \\ &= \frac{2\Re{(z)}}{r^2} \text{ given } |z| = r > 0 \\ &= \frac{2 \times r\cos{x}}{r^2} \text{ given } z = r(\cos{x} + i\sin{x}) \\ &= \frac{2\cos{x}}{r} \end{align*}
Expanding this out...
\begin{align*}
\frac{1}{z} + \frac{1}{\bar{z}} &= \frac{1}{z} \times \frac{\bar{z}}{\bar{z}} + \frac{1}{\bar{z}} \times \frac{z}{z} \\
&= \frac{\bar{z} + z}{z\bar{z}} \\
&= \frac{\bar{z} + z}{|z|^2} \text{ as } z\bar{z} = |z|^2 \\
&= \frac{2\Re{(z)}}{|z|^2} \text{ as } z + \bar{z} = 2 \times \Re{(z)} \\
&= \frac{2\Re{(z)}}{r^2} \text{ given } |z| = r > 0 \\
&= \frac{2 \times r\cos{x}}{r^2} \text{ given } z = r(\cos{x} + i\sin{x}) \\
&= \frac{2\cos{x}}{r}
\end{align*}
- the begin and end align* causes whatever character is preceded by an & to line up, putting the equal signs above each other
- the \frac{x}{y} gives a fraction x over y
- the function \bar{z} displays the conjugate of z
- note that the braces { } are paired and so you must be careful to close each one you open
- the \\ gives a new line (not needed in the line before the \end of align*
- the functions like \Re{(z)} and \cos{x} treat Real part and cosine as functions and displays them
- the \text{xxx yyy} inserts "xxx yyy" as text (including the space) instead of treating it as Maths and showing xxxyyy.
