Pages: 1 2 All. Dialectical behavior therapy (DBT) is a specific type of cognitive-behavioral psychotherapy developed in the late 1980s by psychologist Marsha M. Linehan to help better treat borderline personality disorder.Since its development, it has also been used for the treatment of other kinds of mental health disorders.ialectical behavior therapy (DBT) treatment is a cognitive-behavioral approach that emphasizes the psychosocial aspects of treatment.
The focal length of the mirror is simply the distance between and . As is easily demonstrated, in the paraxial approximation, the focal length of a convex mirror is half of its radius of curvature. There are, again, two alternative methods of locating the image formed by a convex mirror. The first is graphical, and the second analytical. An incident ray which is parallel to the principal axis is reflected as if it came from the virtual focus of the mirror.
Virtual images are always located behind the mirror. Virtual images can be either upright or inverted. Virtual images can be magnified in size, reduced in size or the same size as the object. Virtual images can be formed by concave, convex and plane mirrors. Virtual images are not real; thus you could never see them. Virtual images result when the reflected light rays diverge. Virtual images can be projected onto a sheet of paper.