The average high temperature in Phoenix in January is 50o F. Choose a cosine function representing the temperature over a 1 day cycle that begins at the low temperature. Select one:
a. y = 15 cos2πΘ +35
b. y = - 15 cos2πΘ +35
c. y = 30 cos2πΘ +15
d. y = 30 cos2πΘ +35

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters