Question

Please help?

Answer 1

Which of the following are trigonometric identities?\[A. tanx cosx cscx=1\]\[B. \frac{ secx-cosx }{ secx }=\sin^2x\]\[C. 1-tanxtany=\frac{ \cos(x+y) }{ cosxcosy }\]\[D. 4cosxsinx=2cosx+1-2sinx\]

Answer 2

Which of the following are trigonometric identities?
\[A. \cos^22x+\sin^22x=1\]\[B. \sec^2x+\csc^2x=1\]\[C. \sec^2x-\tan^2x=1\]\[D. \tan^2x-\sec^2x=1\]

Answer 3

Which of the following pairs of coordinates do not represent the same point in polar coordinates?
A. (r,θ) and (-r,θ)
B. (r,θ) and (-r,θ +π )
C. (r,θ) and (-r,θ + 2π)
D. (r,θ) and (r,θ + 2π)

Answer 4

Find all solutions to the equation cosx cos(3x) - sinx sin(3x) = 0 on the interval [0,]. \[A. x=\frac{ \pi }{ 8 },\frac{ 3\pi }{ 8 },\frac{ 5\pi }{ 8 },\frac{ 7\pi }{ 8 },\frac{ 9\pi }{ 8 },\frac{ 11\pi }{ 8 },\frac{ 13\pi }{ 8 },\frac{ 15\pi }{ 8 }\]\[B. x=\frac{ \pi }{ 8 },\frac{ 5\pi }{ 8 },\frac{ 9\pi }{ 8 },\frac{ 13\pi }{ 8 }\]\[C. x=\frac{ 3\pi }{ 8 },\frac{ 7\pi }{ 8 },\frac{ 11\pi }{ 8 },\frac{ 15\pi }{ 8 }\]\[D. x=\frac{ \pi }{ 8 },\frac{ 9\pi }{ 8 },\frac{ 15\pi }{ 8 }\]