\begin{align*} x &= \frac 12 js + \frac 12 is \\\ y &= \frac 14 is - \frac 14 js \end{align*}
How can I find a \begin{align*} i &= \\\ j &= \end{align*} conversion of this?
Edit:
I am not happy with the moderaters assumption on my syntax.
x = (j * s / 2) + (i * s / 2) y = (i * s / 4) - (j * s / 4)
is the proper format.