KPI park or "call to remembrance a Slide Rule" Mystery Cache

I walked through the park of the largest Technical University of Ukraine "Kyiv Polytechnic Institute". I already knew a hiding place. Geocache container is lying in my backpack. This time I wanted to hide a cache for small TB's.

I walked along a cozy  paths of the park and wondered about ideas for the puzzle. Nearby I saw a couple of young students on one of the benches of the park. They are something enthusiastically looked at his tablet computer. I went closer and saw them on the screen of the tablet the color emulator of slide rule! Wow, I thought. In my student days,  each student had a real slide rule and certainly knew how to use it. And now this amazing invention has moved to the computer screen.
Good idea! This invention is to serve people more than 300 years and is worthy to remember about him.
So, to find the exact coordinates of the cache you need to take this formula and refresh one's memory  how to read the results of calculations with the scale of the slide rule.
N 50º A, B
E 30º A, C
where:
A = X³

Hits!

You can check your answers for this puzzle on GeocheckOrg. Click on image pleace

The park is located near the metro station "Politehnichna"
The park is always a lot of Muggles. Be careful!