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°
Easy, find the equation of the line,
Using y=mx+b form:
(-1,3) m=2
3= 2(-1)+b
3= -2+b
+2 +2
5=b
y=2x+5. This is your equation.
Now, plug in the coordinates:
(-3,2)
2= 2(-3)+5
2= -6+5
2= -1
NO
(0,5)
5= 2(0)+5
5=5
YES
(1,5)
5= 2(1)+5
5= 2+5
5=7
NO
(1,4)
4= 2(1)+5
4= 2+5
4=7
NO.
Thus, B, is your answer.
You never told us how much money he has
Answer:
y = 28, 16 , 4 , -8 , -20
Hope this helps.
