1. Use local linear approximation to estimate the value of tan -1(0.03). 2. The production cost (in Php) in manufacturing r air purifiers is C(r) = +104r+2230. 12 The manufacturer's marketing research revealed that unit price should be set at Php 13 12 + + 534 ) in order to sell r units. a. Find the marginal cost in selling the 2015 air purifier. b. How many air purifiers should be produced to maximize profit