#### Question

The total cost C(*x*) associated with the production of *x* units of an item is given by C(*x*) = 0.005*x*^{3} – 0.02*x*^{2} + 30*x* + 5000. Find the marginal cost when 3 units are produced, whereby marginal cost we mean the instantaneous rate of change of total cost at any level of output.

#### Solution

Given that Total coast, C(*x*) = 0.005*x*^{3 }− 0.02*x*^{2 }+ 30*x* + 5000.

We know that marginal cost is the rate of change of total cost with respect to output.

Marginal cost = `(dC)/(dx) = 0.005(3x^2) - 0.02(2x) + 30`

At x = 3 units

`(dC)/(dx) |_(x = 3) = 0.005 (3 xx (3)^3) - 0.02 (2 xx 3) + 30`

=> (dC)/(dx) |_x = 3 = 0.135 - 0.12 + 30 = 30.015

Thus, the required marginal cost when 3 units are produced is Rs 30.015.

Is there an error in this question or solution?

Solution The Total Cost C(X) Associated with the Production Of X Units of an Item is Given by C(X) = 0.005x3 – 0.02x2 + 30x + 5000. Find the Marginal Cost When 3 Units Are Produced, Whereby Marginal Cost We Mean the Instantaneous Rate of Change of Total Cost at Any Level of Output. Concept: Rate of Change of Bodies Or Quantities.