Answer:
The answer for first one is,
sorry I don't know the answer for second one.
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:
T=5
Step-by-step explanation:
4t+90=110
4t=20
t=5
Answer:
The answer is $86 in all.
Step-by-step explanation:
What you first do is make the problem into a equation which would be
($25 + $25) + ($16 + $16)
or if you are at a more advance level it would be
2($25 + $16)
in word form it would be , add $25 and $16 two times for a total of $86 in total.
Answer:
So
A = 94
B = 200
C = 221
Angle A = 25.174
Angle B = 64.83
Step-by-step explanation:
Angle B is the top corner, while Angle A is the Bottom corner
Side C is the longest side
Side A is the smallest and goes up
Side B is the bottom side