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:
22,40,62
Step-by-step explanation:
0+2=2 2+6=8 8+10=18
2 6 10 14 18 22 four in between
so you will add these numbers each time
18+14=22 22+18=40 40+22=62
I am assuming this is a triangle.....P = a + b + c
P = 2a - 3 + 2a + 3a + 1....combine like terms
P = 7a - 2 <==
Answer:
y=− 2x−8 is the equation
Step-by-step explanation:
equation for slope is y=mx+b the y intercept is -8 and the slope is -2
