Let the production function for deer be:

f(x_1,x_2) = (2x_1 + x_2)^1/2

where x1 is the amount of plastic and x2 is the amount of wood used.

If the cost of plastic is $4 per unit and the cost of wood is $4 per unit, then the cost of producing 8 deer is:

I am having a hard time with the calculus part of finding the two partial derivatives of the production function.