The marginal cost of making $x$ units is $4x + 9$ rupees, and the fixed cost is ₹250. What is the total cost function?

Explanation

1. 01

   $C(x) = \int (4x + 9)\,dx = 2x^{2} + 9x + K$.

2. 02

   The constant is the fixed cost, $C(0) = 250$: $C(x) = 2x^{2} + 9x + 250$.