# What is the slope of the line normal to the tangent line of #f(x) = cos(2x)*sin(2x-pi/12) # at # x= pi/3 #?

##### 1 Answer

Jan 6, 2016

#### Explanation:

Using the product rule, we can find the derivative or the "slope function" of

Just to make it a bit neater, we can use the expansion formula for

Hence,

Now, that's the slope of the tangent, the slope of the normal would be the negative reciprocal of that, in other words,

Hence,