(3·COT(x) - 3/x) / (2·x)
= (3·x·COT(x)/x - 3/x) / (2·x)
= ((3·x·COT(x) - 3)/x) / (2·x)
= (3·x·COT(x) - 3) / (2·x^2)
= 3·(x·COT(x) - 1) / (2·x^2)
So könntest du es auch stehen lassen.
= 3·(x·COS(x)/SIN(x) - 1) / (2·x^2)
= 3·(x·COS(x)/SIN(x) - SIN(x)/SIN(x)) / (2·x^2)
= 3·((x·COS(x) - SIN(x))/SIN(x)) / (2·x^2)
= 3·(x·COS(x) - SIN(x)) / (2·x^2·SIN(x))
So hatte ich es notiert.