$\"\"$

Cost of producing $\"\"$ ounces of gold from a new gold mine is $\"\"$ .

(a) The derivative $\"\"$ is the rate of change of $\"\"$ with respect to $\"\"$ .

So the rate of cost function $\"\"$ is

$\"\"$ .

The above expression represents the rate of cost per ounce of produced gold from mine.

The units are dollars per ounce.

(b) The statement is $\"\"$ .

Rate of change of cost function at $\"\"$ ounce of gold is 17 dollar/oz.

(c) The gold mine is new it is easy to extract the gold as plenty of obtainable gold deposits are available in short period of time

So the rate of change of cost decreases and in long term fro large scale operations $\"\"$ may increase.

(a) The derivative expression $\"\"$ means that rate of cost is changing per ounce of produced gold from mine and the units are dollars per ounce.

(b) Rate of change of cost function at $\"\"$ ounce of gold is 17 dollar/oz.