Assume the radius of a circle is
1 answer:
Answer:
Step-by-step explanation:
They want you to see how radius is important. Just remember that one radian is one radius, that should help you see why radius is important.
They ask for the unit circle , that is a circle of one unit for the radius, which makes it super easy to calculate things for it, they ask what is the area, which is that famous formula, π , then they ask what's its circumference. which is that other famous formula 2πr
so to go all the way around a circle of one unit radius, it's 2π exactly or about 6.28..... units, call it meters, or feet or inches, it doesn't mater here.
the size of the circle doesn't matter here either, b/c we are using the radius , that relaationship doesn't change , all circles, what ever size , have this same relationship between the radius and radians. :P this is handy.
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Answer:
The lines intersect at x = 1.5 and y = 1
Step-by-step explanation:
We need to find the intersection of the lines 2x+5y=8 and 6x+y=10.
We need to find the values of x and y by elimination and by substitution.
a) By Elimination:
2x+5y = 8 (1)
6x + y = 10 (2)
Multiply eq(2) with 5 and subtract eq(1) from(2)
30x + 5y = 50
2x + 5y = 8
- - -
___________
28x = 42
x = 1.5
Now putting value of x in eq(2)
6x + y = 10
6(1.5) + y = 10
9 + y = 10
=> y = 10 - 9
y = 1
so, (x,y) = (1.5,1)
The lines intersect at x = 1.5 and y = 1
b) By substitution
2x+5y = 8 (1)
6x + y = 10 (2)
Finding value of y in equation 2 and substituting in eq(1)
y = 10 -6x
2x + 5(10 - 6x) = 8
2x + 50 - 30x = 8
-28x = 8-50
-28x = -42
x = -42/-28
x = 1.5
Now finding value of y by substituting value of x
6x + y = 10
6x = 10-y
x = 10 - y /6
2x + 5y = 8
2(10-y/6) + 5y = 8
10-y/3 + 5y = 8
10 -y +15y/3 = 8
10 +14y = 8*3
+14 y = 24 -10
+14 y = 14
y = 14/14
y = 1
So, (x,y) = (1.5,1)
The lines intersect at x = 1.5 and y = 1
Answer: 29000 people went in 1981.
Step-by-step explanation:
Let x= Attendance in 1981.
Given: The average attendance of Everton football club fell by 7% in 1982.
Difference in attendance from 1981 to 1982 = 0.07x
If 2030 fewer people went to matches in 1982,
Hence, 29000 people went in 1981.