Trigonometry
posted by Rodrick .
im stuck on these questions.......
6. Change 4√2  4√2 to trigonometric form
A. 32 cis 135°
B. 8 cis 225°
C. 8 cis 45°
D. 32 cis 45°
7. Simplify (2 cis 100°)7.
A. 2 cis 700°
B. 128 cis 280°
C. 128 cis 340°
D. 2 cis 340°
9. Simplify
12(cos52° + i sin52°)/8(cos128°+isin128°)
16. Which of the following statements are true?
(i) r = 4 – 3 sin θ is the equation for a limaçon rotated 90°.
(ii) r = 3 cos 8θ is the equation for a rose curve with 8 petals.
(iii) rθ = 16 is the equation for a circle.
A. (ii) only
B. (i) only
C. (i) and (ii)
D. (i) and (iii)
17. Describe the rotation required to transform the graph of r = 4 − cos (θ − 30°) sin (θ − 30°) to the graph of r = 4 − cos θ sin θ.
A. 30° counterclockwise
B. 60° clockwise
C. 60° counterclockwise
D. 30° clockwise
18. Simplify (4 − 9i ) − (2 − 4i ).
A. 2 − 13i
B. 2 − 5i
C. −5 + 2i
D. 2 + 13i

6. since both x and y are negative, we are in QIII, so (C). Luckily r=8 fits as well.
7. (C): 2^7 cis(7*100) = 128 cis 340
9. 12/8 cis(52128) = 3/2 cis 76
16. (B)
17. (D)
18. (B)