cscx-sinx=(cotx)(cosx) ... and more of those

[LaurenCampbell]

prove:

1. cscx - sinx = (cotx)(cosx)
2. sinx + (cotx) (cosx) = cscx

*please find:

A. sin(B+A)
B. cos(A-B)
C. tan(A+B)
D. sin (2A)
E. Tan (2a)
F. Cos (2b)

 

[stapel]

For the identities, an often-useful first step is to convert everything to sines and cosines, and see where that leads. What have you tried so far?

For the "please find" exercises, without values for A, B, a, and b, these expressions cannot be evaluated. Sorry.

Eliz.