The total revenue in Rupees received from the sale of x units of a product is given by

R(x) = 13x² + 26x + 15.

Find the marginal revenue when x = 7.

Sand is pouring from a pipe at the rate of 12 cm³/s. The falling sand forms a cone on the ground in such a way that the height of the cone is always one-sixth of the radius of the base. How fast is the height of the sand cone increasing when the height is 4 cm?

The total cost C(x) in Rupees associated with the production of x units of an item is given by

C(x) = 0.007x³ – 0.003x² + 15x + 4000.

Find the marginal cost when 17 units are produced.

The rate of change of the area of a circle with respect to its radius r at r = 6 cm is

The total revenue in Rupees received from the sale of x units of a product is given by

R(x) = 3x² + 36x + 5. The marginal revenue, when x = 15 is