Question

focus of the concave mirror is always real why​

Answer 1

Explanation:

Reflection from a Concave Mirror

The image is real light rays actually focus at the image location). As the object moves towards the mirror the image location moves further away from the mirror and the image size grows (but the image is still inverted). When the object is that the focal point, the image is at infinity.

Answer 2

because the image formed in it us real and inverted