Verify the following formula for the third derivative of a product, where f and g are di...

Verify the following formula for the third derivative of a product, where f and g are differentiable functions of x:

[Hint: Differentiate the formula in Exercise 57 by the Product Rule.]

REF PRB:

Verify the following formula for the second derivative of a product, where f and g are differentiable functions of x:

[Hint: Use the Product Rule repeatedly.]