Find the measurement of the reference angle of an angle measuring 5 pi divided by 4.

Answears

a. pi/2

b.-pi/2

c.pi/4

d. - pi/4

step by step explanation is 100% wanted and I will give thanks!

& just so I don't make another board. ..

Write cos 6x cos x - sin 6x sin x in terms of a single.. trigonometric function.. i only got to cos 7x - sin 7x

and write 2 cos(squared) 2 theta - 1 in terms of a single trigonometric function.

Use the half angle identity to evaluate tan 67.5degrees.

if i do tan(67.5dividedby 2) = sin67.5divided by 1+ cos67.5 how do i get

a.2squareroot(2)-2

b.squareroot(2) +1

c.squareroot(2) - 1

d. 2 - squareroot(2)

Find the exact value of cos 2 theta given that sin theta = - 3 divided by 5 and theta is in quadrant III,.

and last one i promiss after i get help with these i will try to help others to warm me up for my finals!

a. - 7/25

b. 7/25

c. 17/25

d. -17/25

please don't just give the answear but explain things! THAnKS!!