Please show work and explanation

7. (a) Find the .rvalues for which the functions f below change concavity or show that no such :1:Values exist. Figure 2: graph of y : Jetty) \=.' (u 10. * "A box has a square base of side :13 and height h. (a) * Find the dimensions 3:, h. for which the volume is 16 and the surface area is as small as possible. (b) Find the dimensions :L', h for which the volume is 11 and the surface area is as small as possible