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
Answer:
idk how to do that try to slove it
but I didn't get right answer
Answer:mn jjjjjjjjjjjjjjjjjjjjjjjj,uyhhhbgfvStep-by-step explanation:
Omg, im so sorry, i was moving and put my books on top of my keyboard it did this. Sorry. SOMEBODY DELETE THIS PLEASE. Sorry again.
There are 160 fluid ounces in 5 quarts. Because there are 32 fluid ounces in 1 quart multiply that by 5 and you get 160. Your welcome!!!
