Just be warned that this will only produce a ‘valid’ approximation for about 0 < x < 2.
Edit: Since icode^2 / p[/icode] and icode^2[/icode] should both be calculated per light (correct, or am I thinking of this variable wrong?), this optimization matters less than the optimization of the equation [icode]y=s/(x^2+t)[/icode] where [icode]s=(plnp)^2[/icode] and [icode]t=(plnp)^2/p[/icode].
Ps: also not gonna use latex sorry not sorry