Describe two ways of detecting black holes in space.

Since black holes deal with dark matter and dark energy and are dark enough not to allow even light to escape them, so their detection is much more difficult.

There are two basic methods to detect a black hole in space and these are listed below:

One way is to determine on the basis of strong influence of gravity that the black holes have due to their no bound dense masses
Another way to detect a black hole is through observation of a falling matter into the black hole. Matter, after falling into the black hole settles in a disk around it. The temperature of the disc can sometimes hike to extreme hot temperatures. Some amount of energy due to trap matter inside is liberated and turns into light which can be seen as in X-rays.