Answer:
90°
Step-by-step explanation:
please mark brainliest :))
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:
Ice Cube, Liquid Water, and Steam
Step-by-step explanation:
An example of a solid is a ice cube, the particles are compacted together and there's very little movement.
An example of a liquid is water, the particles are more spread around and the movement is more frequent.
An example of a gas is steam, the particles are anywhere, moving fast and sporadic.
Answer:4/125
Step-by-step explanation:
we have given an expression 
.
we have given the value of x,y and m .
.
we need to find the value of expression mx-y.
we need to plug the respective values and solve.
.
7 is the value of expression mx-y.
