How to design acos, atan, and a division blocks in Dsp Builder

I doubt, if DSPBuilder has particular means to help with trigonometric functions, cause it's not involved with signal processing generally.

Usual methods are either LUTs or iterative algorithms, mostly the latter for higher precision, e. g. with numeric processors. LUT can operate directly or use linear interpolation. Key parameters to select a suitable method are speed, precision and numeric range.

The standard (parallel) divider Megafuntion is suited also for remainder only calculation, you can expect a reduction of LE requirement compared to the full utilzed divider. If you don't run short of resources, the parallel divider is a simple solution.

Serial dividers may be used for different speed and resource tradeoff. Special algorithms for calculating the remainder probably exist, cause they play an important role in NP mathematics.