Made4Us Inc. makes lithium battery for handheld computers. The factory requires all the products to conform a specification with no more than 14 ± 0.1 watts at peak use. Exceeding these limits results in an estimated loss of $50. However, the manufacturer can adjust the wattage in the manufactoring process by changing the circuit at a cost of $4. 

a. Determine the Taguchi loss function. 

b. Given the nominal specification is 14 watts, determine the optimal tolerance level should the integrated circuit be manufactured.