The equation is

a=1

b=0.2

v=12.56

u=2

x=a*cos(v)*sin(u)

y=a*sin(v)*sin(u)

z=a*(cos(u)+log(tan(u/2)))+b*v

View attachment 42

I think it needs some tweaking, pro e accepts it as no errors in the equation but it needs resolving it cant be created as yet! Any ideas?

I wasnt sure if pro e accepted the term 'log' ?

Thanks

=)