Question

do 2. A photographer uses a light meter to measure the intensity of light from a flash bulb. The intensity for the flash bulb, 1, in lux, is a function of the distance from the light, d, in metres, and can be represented by Id) 10 .d > 0 a) Determine the following, to two decimal places. i) the average rate of change in the intensity of light for the interval 1 <d <3 ii) the approximate instantaneous rate of change in the intensity of light at exactly 8 m from the flash bulb. b) What does the sign of your answer to part a), subpart ii), indicate about the light intensity?