Question

What is the derivative of sec(x)^2

Answer 1

This is also written as sec^2(x)
Using chain rule, we can separate this into 2sec(x)*d/dx(sec(x))
Using trig derivative identities, we know that d/dx(sec(x))=tan(x)sec(x)
Therefore, we have 2sec(x)*tan(x)sec(x), which simplifies down to 2tan(x)sec^2(x).  

Hope this helps!