4.04 Unit Test: Trigonometric Identities Part 1

These are ONLY the questions I got right on the test! :) : Of course I can't give you the answers to the ones I got wrong, because they're wrong.

Cot^2x - tan^2x = 1 for all values of x : False

_____cos B = 1/2 [cos(A+B)+cos (A-B)] : cos A

Find the exact value of cos (11pi/8). : -sqrt[2-sqrt(2)/4]

If sinx=5/13 and x is in quadrant 1, then sin x/2=____. : sqrt(1/26)

If sin x=-3/5 and x is in quadrant 3, then tan 2x=___. : 24/7