∫ f'(x)(af(x) + b)n dx = (af(x) + b)n + 1/[a(n + 1)] + C
C is the constant of integration.
Marginal cost - the derivative of the cost function with respect to quantity. Average cost - the cost function divided by quantity (q).
∫ [1/[f(x)(f(x) ± g(x))]] dx = ±∫1/[f(x)g(x)] dx ± (-1)∫ [1/[g(x)(f(x) ± g(x))]] dx
∫ f'(x)/√(af(x) + b) dx = 2√(af(x) + b)/a + C C is the constant of integration.
∫ f'(x)/√[f(x)2 + a] dx = ln[f(x) + √(f(x)2 + a)] + C C is the constant of integration.
The spacial derivative is the measure of a quantity as and how it is being changed in space. This is different from a temporal derivative and partial derivative.
Increase in cost: take the first derivative with respect to the unit produced of a cost function. Total cost: sub-in the new quantity into the cost function.
∫ f'(x)/(p2 + q2f(x)2) dx = [1/(pq)]arctan(qf(x)/p)
The cost of increasing the production by one unit. Mathematically, this can be derived as the derivative of the total costs with respect to quantity i.e. dc(q)/dq, where c(q) is the cost function and q is quantity.
∫ [f'(x)g(x) - g'(x)f(x)]/g(x)2 dx = f(x)/g(x) + C C is the constant of integration.
∫ f'(x)/( q2f(x)2 - p2) dx = [1/(2pq)ln[(qf(x) - p)/(qf(x) + p)]
∫ [f'(x)g(x) - g'(x)f(x)]/[f(x)g(x)] dx = ln(f(x)/g(x)) + C C is the constant of integration.
Marginal cost = derivative of (Total cost/Quantity) Where Total cost = fixed cost + variable cost Marginal cost = derivative (Variable cost/Quantity) (by definition, fixed costs do not vary with quantity produced) Average cost = Total cost/Quantity The rate of change of average cost is equivalent to its derivative. Thus, AC' = derivative(Total cost/Quantity) => derivative (Variable cost/Quantity) = MC. So, when MC is increasing, AC' is increasing. That is, when marginal cost increases, the rate of change of average cost must increase, so average cost is always increasing when marginal cost is increasing.