Question

What are the double angle formulas for csc and sec?

Answer 1

Generally these are best calculated by changing them to sines and cosines

None of the first 4 pages I looked at after "googling" double angle formulas gave me a formula for csc 2x or sec 2x

We could however find them:
change csc 2x to 1/sin 2x
= 1/(2sinxcosx)
=1/2(cscx)(secx)

similarly

sec 2x = 1/cos2x
= 1/(cos^2 x - sin^2 x)

Answer 2

Thanks!