Respuesta :

inflection points occur where the graph changes direction

so

26.(-4,5) (-0.5,-5) (4,2) (6,-1)

is concave up when there is a valley between two points

so

27.(-2,2) and (5,8)

is concave down when there is a mountain between two points

so

28. (-6,-2) and (2,5)