80=x+3x
80=4x
20=x
There are 20 girls.
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:
46.5
Step-by-step explanation:
i divided 93 by 2 and got 46.5
hope this helps :)
Answer:
Step-by-step explanation:
if center=(h,k)
radius=r
eq. of circle is (x-h)^2+(y-k)^2=r^2
given eq. is (x-5)^2+(y+2)^2=16=4^2
comparing
center =(5,-2)
radius r=4
