Applications of Derivatives in Economics Quiz

What is marginal cost?

• Total cost divided by quantity

• Rate of change of total cost with respect to quantity produced

• Total profit at output x

• Fixed cost per unit

If C(x) = 500 + 20x, the marginal cost MC(x) is:

• 500

• 20x

• 20

• 520

Marginal revenue (MR) is the derivative of total revenue with respect to quantity.

• True

• False

Which statement is true about the slope of the tangent to a revenue curve at a point?

• It gives the average revenue at that output

• It gives the marginal revenue (instantaneous change in revenue)

• It gives the total revenue up to that point

• It gives the fixed cost

The demand function D(p)=120-3p. At price p=10, the elasticity of demand is:

• -3

• -1/3

• -0.1

• • - 10/120

Given revenue R(x)=100x - 2x². The marginal revenue MR(x) is:

• 100x - 4x²

• 100 - 4x

• 100 - 2x

• 200x - 2x²

If MR(x) > MC(x) at output x, the profit-maximizing rule suggests:

• Produce less (reduce output)

• Produce more (increase output)

• Stop production immediately

• Marginal profit is zero

Marginal profit is equal to:

• R(x) - C(x)

• dR/dx - dC/dx

• d²R/dx²

• (R(x) - C(x))/x

If total cost C(x)=2x² + 10x + 50, find MC(x).

• 4x + 10

• 2x + 10

• 4x² + 10

• 2x² + 10x

A function f(x) has derivative f'(x) = 3x - 6. On which interval is f increasing?

• x > 2

• x = 2

• For all x

• x < 2