8-Which of the following counterexamples proves that csc xtan x = cos x is not a trignometric identity. Select all that apply

A) 0 B) pi4 C) pi3 D) 2pi

9- Which of the following possible trigonometric identities can be verified. Select all that apply

A) cosxtanx = sinx B) tanxsecxsinx = 1 C) tanxcscxsinx = 1 D) cscxcotxsecx = csc^2 x

10- Which of the following possible trigonometric identities can be verified. Select all that apply

A) cotx + tanx = secxcscx B) cotx + 2 = cosxcscx C) sin^4 x - cos^4 x = 2sinx^2 x - 1 D) cotxsinx = cscx