Sponsor Area

Application Of Derivatives

Question
CBSEENMA12034966

The cost function C(x), in rupees, of producing x items (x ≥ 15) in a certain factory is given by straight C left parenthesis straight x right parenthesis space equals space 20 plus 10 straight x squared plus 15 over straight x.  Determine the marginal cost function and the marginal cost of producing 100 items. 

Solution

Here,   straight C left parenthesis straight x right parenthesis space equals space 20 plus 10 straight x squared plus 15 over straight x space space space space rightwards double arrow space space space space space space straight C space equals space 20 plus 10 straight x squared plus 15 straight x to the power of negative 1 end exponent
Marginal cost function equals space dC over dx space equals space 0 plus 20 straight x minus 15 straight x to the power of negative 2 end exponent space equals space 20 straight x minus space 15 over straight x squared
When x = 100,  marginal cost  = 20 (100)  - fraction numerator 15 over denominator left parenthesis 100 right parenthesis squared end fraction
                                            equals space 2000 minus 15 over 10000 space equals space left parenthesis 2000 minus.001 right parenthesis space nearly space equals space Rs. space 2000 space nearly.