Answer:
it's -7
Step-by-step explanation:
calculate the values
Answer:
(i) 1/6
(ii) 1/6
(iii) 4/6 = 2/3
(iv) 3/6 = 1/2
(v) 3/6 = 1/2
(vi) 0/6 = 0
Its A = If you want to know how I did it subtract 62-22 then what ever you get multiply it by 4 then Carry on from their
1. 1/a^8 (Sorry I can't find out what the others are)
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
