Answer : A concave mirror is used to converge the light and a convex mirror is used to diverge the light.
Explanation :
Convex mirror : In convex mirror, the mirror is coated inside the spherical surface. It is also known as a converging mirror.
The focus lies behind the mirror.
Concave mirrors : In concave mirror, the mirror is coated outside the spherical surface. It is also known as a diverging mirror.
The focus lies infront the mirror.
As per question, a concave mirror is used to converge the light and a convex mirror is used to diverge the light.
Hence, a concave mirror is used to converge the light and a convex mirror is used to diverge the light.