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:
4
Step-by-step explanation:
Step-by-step explanation:
Using Binomial Expansion,
(x + y)³
= 3C0 * x³ + 3C1 * x²y + 3C2 * xy² + 3C3 * y³.
Therefore the coefficient of xy² is 3C2 = 3.
Hey! You just have to square root the 2 and 5 then multiply by 11 so the answer I came up with is 34.78505426185218
I hope I helped!
Answer:
20 students are sitting in the library
Step-by-step explanation:
4 · 5 = 20
