12. A photographer uses a light meter to measure the intensity of light from a flash bulb. The intensity for the flash bulb, /, in lux, is a function of the distance from the light, d, in metres, and can be represented by Id) _ 10 .d > o. a) Determine the following, to two decimal places. i) the intensity of light 3 m from the flash bulb ii) the average rate of change in the intensity of light for the interval 1