1 Chills and Tingling fingers and Skin symptoms (4 causes) 2  Chills and Tingling fingers and Temperature symptoms (4 causes) 3  Chills and Tingling fingers and Body symptoms (3 causes) 4  Chills and Tingling fingers and Leg symptoms (3 causes)  Chills and Tingling fingers and Limb symptoms (3 causes)
From the geometry of the spherical mirror, note that the focal length is half the radius of curvature: As in the case of lenses, the cartesian sign convention is used here, and that is the origin of the negative sign above. The radius r for a concave mirror is a negative quantity (going left from the surface), and this gives a positive focal length, implying convergence.
Assemble the Frame. Measure and mark a 24-inch by 30-inch rectangle at the center of the plywood piece. Apply construction adhesive on the back side of the mirror and place it on top of the marked section of the plywood. Ascertain that a length of 3 inches is left all round the attached mirror. Place a relatively heavy material such as books on top of the mirror and leave the glue to dry for about five hours.