Answer is 5/29. Because 3/29 + 2/29=5/29
cos (2x) = cos x
2 cos^2 x -1 = cos x using the double angle formula
2 cos ^2 x -cos x -1 =0
factor
(2 cos x+1) ( cos x -1) = 0
using the zero product property
2 cos x+1 =0 cos x -1 =0
2 cos x = -1 cos x =1
cos x = -1/2 cos x=1
taking the arccos of each side
arccos cos x = arccos (-1/2) arccos cos x = arccos 1
x = 120 degrees x=-120 degrees x=0
remember you get 2 values ( 2nd and 3rd quadrant)
these are the principal values
now we need to add 360
x = 120+ 360n x=-120+ 360n x = 0 + 360n where n is an integer
The answer is -5. -5 times 4 is -20, plus 9 is -11. -5 times 2 is -10, -1 is -11. -5 works.
Answer:
Number A. is True. B. is False. C. is IDK D. is False. E. is true.
Step-by-step explanation:
If you read it you can tell plus I broke it down and solved it on paper.
11,513 is the answer I really don't know how to write it all out sorry
