How to find a point on the far side of the Earth?

Question

Mathematics

Good afternoon friends. I once asked a question and did not get an exact answer to it.
How, knowing the coordinates of a point, get the coordinates of another point, which is located on the opposite side of the Earth (with, as it were, a line passing through the center of the Earth).
Who fumbles, please write a formula for decimal coordinates, if for example the starting point is:
58.603671, 49.656992 (according to Yandex)

Answer 1

The latitude will be opposite and the longitude will be 180 degrees different.
The opposite point to 58.603671, 49.656992 is -58.603671, −130.343008 .