Answer: 57%
Step-by-step explanation:
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:
9-5 or 1/4-5
Step-by-step explanation:
A line that is parallel to another line will have the same slope, in our case, the slope of 3. Therefore, we can just change the y-intercept to create any line parallel to y=3x+5 (just remember to keep the slope the same). For example, y=3x+5, y=3x-9, and y=3x+6.2 are all equations that are parallel to y=3x+5.
:)
