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:
d=252m, u dint put the speed it was rolling at from point B to C so I could only solve for A to B. However if you use the formula below you can find the distance from B to C and add that to A to B giving the total distance rolled.
Step-by-step explanation:
d=vt
v=14m/s
t=18s
d= vt, (14m/s)(18s)
d=252m
Answer:8(3+2)
Step-by-step explanation: Find gcf which is 8 then think what 24 divide 8 equal and think what 16 divide 8 equals.
Answer:
(23, 4)
Step-by-step explanation:
If we use substitution, we need to rewrite the 2nd equation so we can substitute it into the first.
Step 1: Rewrite 2nd equation
x = 5y + 3
Step 2: Substitution
2(5y + 3) - 5y = 26
Step 3: Distribute
10y + 6 - 5y = 26
Step 4: Combine like terms
5y + 6 = 26
Step 5: Isolate <em>y</em>
5y = 20
y = 4
Step 6: Find <em>x</em>
x - 5(4) = 3
x - 20 = 3
x = 23
And we have our final answer!
Answethere should be an answer key online
Step-by-step explanation:
