What is best supported by the rate of change

The parabola opens: y=√x-4 (principal square root) up down right left

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b

Which strategy is used by public health to reduce the incidence of food poisoning?