Answer:
Step-by-step explanation:
cos (x/2)=cos x+1
cos (x/2)=2cos ²(x/2)
2 cos²(x/2)-cos (x/2)=0
cos (x/2)[2 cos (x/2)-1]=0
cos (x/2)=0=cos π/2,cos (3π/2)=cos (2nπ+π/2),cos(2nπ+3π/2)
x/2=2nπ+π/2,2nπ+3π/2
x=4nπ+π,4nπ+3π
n=0,1,2,...
x=π,3π
or x=180°,540°,...
180°∈[0,360]
so x=180°
or
2cos(x/2)-1=0
cos (x/2)=1/2=cos60,cos (360-60)=cos 60,cos 300=cos (360n+60),cos (360n+300)
x/2=360n+60,360n+300
x=720n+120,720n+300
n=0,1,2,...
x=120,300,840,1020,...
only 120° and 300° ∈[0,360°]
Hence x=120°,180°,300°
Let x = # of 25-cent stamps
y = # of 2-cent stamps
{ x+ y = 88
{ 0.25x + 0.02y = 15.56
60 25-cent stamps 28 2-cent stamps
Answer:
200 in.
Step-by-step explanation:
1250/75=5000/300=50/3 simplification
50*12=600 conversion to inches
600/3=200 simplification
Answer:
Step-by-step explanation:
The last answer choice is the correct one. The common ratio here is 0.7, which is between 0 and 1, an important criterion for recognizing an exponential decal function. Every time x increases, f(x) will decrease.
Answer:
y=19/16 or y=1.1875
Step-by-step explanation:
