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 ratio is called the Opposite leg or also known as Hypotenuse. Usually, in a right angle, the size of the one angle is 90 degrees while the other which is less than 90 degrees is called the hypotenuse. It is the opposite side of the angle measured 90 degrees
Answer:
A. $258.00
Step-by-step explanation:
There are 12 months in a year so you will simply have to multiply $21.50 by 12
21.50 x 12
258
Answer:
550-554
Step-by-step explanation:
550 is rounded to 550, and also rounded to 600. Same with all the other numbers. :)
Answer:
12/5 is 2.4 so
9 girls I think.
Step-by-step explanation:
