2. Write the 3 Pythagorean Identities

Which of the following is a pair of equivalent radical expressions? A) radical 45 and radical 15 Radical 75 an radical 3 5 Radical 54 and radical 9 6 Radical 180 and radical 3 20

Verify the identity. sec x- tan 2x = sec x- tan x sec x+ tan x Which of the following four statements establishes the identity? O A. sec x- tan 2 (sec x- tan x)( sec x- tan x) = sec x- tan x sec x+ tan x sec x+ tan x O B. 2 sec x- tanx (sec x- tan x)( sec x+ tan x) = sec x- tan x sec x+ tan x sec x- tan x OC. sec x- tan x 2 sec x tanx = sec x- tan x sec x+ tan x sec x tan x O D. sec2 x- tanx (sec x- tan x)( sec x+ tan x) = sec x- tan x sec x+ tan x sec x+ tan x

k + 2 7. Assume csc B and ZB is in the second k - 2 quadrant. a) Find the expression for cos B. b) What are the restrictions on k?