Question

The cost (in rupees) of producing x items in the factory each day is given by C(x) = 0.00013x³ + 0.002x² + 5x + 2000.

Find the marginal cost when 150 items are produced.

Answer 1

C(x) = 0.00013x³ + 0.002x² + 5x + 2000

C'(x) =  0.00013 × 3x³ + 0.002 × 2x + 5

At x = 150

C'(150) = 0.00039 × (150)² + 0.004 × (150) + 5

= 0.00039 × 22500 + 0.6 + 5

= 8.775 + 0.6 + 5

= ₹ 14.375