# Question #44491

##### 1 Answer

Feb 23, 2017

#### Answer:

This is a product of three functions.

#### Explanation:

I use the product rule in the order:

(The derivative of a product is the derivative of the first times the second, plus the first times the derivative of the second.)

For three functions, we have

# = u'vw+u(v'w+vw')#

# = u'vw+uv'w+uvw'#

For four functions

In this question

so,

# = cos theta sin theta + theta( cos^2 theta - sin^2 theta)#

The quantity in parentheses is equal to