Question

Given the total cost function, $TC=a+bQ+c{Q}^2+d{Q}^3$, Find the Marginal cost.

• A. $b+2cQ+3d{Q}^2$
• B. $a+b+2cQ+3d{Q}^2$
• C. $a+2b+2cQ+3d{Q}^2$
• D. None

Answer 1

The correct option is A $b+2cQ+3d{Q}^2$

$\Rightarrow$ We have $TC=a+bQ+c{Q}^2+d{Q}^3$

$\Rightarrow$ $Marginalcost=\frac{d}{dQ}TC$

$\Rightarrow$ $Marginalcost=\frac{d}{dQ}(a+bQ+c{Q}^2+d{Q}^3)$

$\therefore$ $Marginalcost=b+2cQ+3d{Q}^2$