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°
Answer: the length of the base is 15 kilometers.
Step-by-step explanation:
formula : Area of parrallelogram = Length of base x height
Given: Area of parallelogram = 300 square kilometers
height = 20 kilometers
Substituting values in the formula , we get
300 = Length of base x 20
Length of base = 
= 15 kilometers
Hence, the length of the base is 15 kilometers.
Answer:
choice 1
Step-by-step explanation:
angle 1 = angle 7 (exterior alternate angle)
angle 3=angle 5 (interior alternate angle)
50% off means half price, so half of 49.98 is 24.99
the necklace now costs 24.99 dollars
Answer:
what is the question
Step-by-step explanation:
