The 3 inside angles need to equal 180.
Subtract E from 180 to find the sum of the other two angles:
180 - 104 = 76
Now because EF ≅ DE , angle D and F would be the same so divide 76 by 2
Angle D = 38
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
A - 24!
-21 as its true value is 21
-3 as its true value is 3
if you add them together you get 24!
Hope this helped ^^
Answer:
Don't fail
Step-by-step explanation:
Answer:
B is your answer
Step-by-step explanation: