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:
m+49=d ; d-49 = m
Step-by-step explanation:
Jim $ = m
Keenan $ = d
m+49=d ; d-49=m
btw please lmk if i get this wrong
79.881 hope this helps
i might be wrong

The given pair of angles are vertical opposite angle pair so, they are equal. i.e
Answer:
B. y = 0.097x + 11.142
Step-by-step explanation:
In order to find the best equation to descibe the housing price, we have to calculate the slope of the line first.
The equation of the line can be written as

where m is the slope and q the y-intercept.
In order to have the most accurate estimate for the slope, we use the first point and the last point, that are:
(1900, 196)
and
(2200, 225)
The slope of the line is calculated as:

So, the slope of the line is 0.097.
Therefore, the correct option is the only one having a slope of 0.097, which is:
B. y = 0.097x + 11.142