The function declaration varies according to , but the input function only contains the variable . Assume .

Since is constant with respect to , the derivative of with respect to is .

To apply the Chain Rule, set as .

The derivative of with respect to is .

Replace all occurrences of with .

Multiply by .

Since is constant with respect to , the derivative of with respect to is .

Multiply by .

Differentiate using the Power Rule which states that is where .

Multiply by .

Find the Derivative f(x)=2cos(2y)