Answer:
1) 69.5
2) 678.6
Step-by-step explanation:
pi3^2=28.27*9=254.5 18*18=324-254.5=69.5
pi24^2=1809.6*.5=904.8 pi6^2=113.1*.5=56.55*4=226.2 904.8-226.2=678.6
Alice receives 9 out of the 24 pens.
Answer:
36years
Step-by-step explanation:
Let charity present age be x
Charity daughter present age be y
Charity husband present age be z
If the sum of their ages ten years to come is 117, then;
10+x+10+y+10+z = 117
30+x+y+z = 117
x+y+z = 87 ... 1
If charity is four times as old as her daughter, then;
x = 4y
y = x/4 ... 2
If she is also six years younger than her husband, then;
x = z- 6
z = x+6 .. 3
Substitute 2 and 3 into 1;
x + x/4 + (x+6) = 87
Multiply through by 4
4x + x + 4(x+6) = 4(87)
5x+4x+24 = 348
9x = 348 - 24
9x = 324
x = 324/9
x = 36
hence Charity is 36years old today
Answer:
This is a radioactive decay / half-life problem.
Initial amount of C 14 = 100% Present Amount = 57%
k = .0001 (that value should be negative)
Nt = No * e^ (k*t)
You need to solve that equation for "time" (equation attached)
time = natural log (Ending amount / Starting Amount) / k
time = natural log (57% / 100%) / -.0001
time = ln (.57) / -.0001
time = -.56211891815 / -.0001
time = 5,621.2 years (age of the bird skeleton)
These problems are quite complicated but I think I know this pretty well.
Need to know more? Visit my website (it's on the graphic).
Step-by-step explanation:
Part 1: The general form for this matches y^2 = -4cx, which implies that this opens to the left. (Imagine assigning any value of y, whether positive or negative, which would result in a positive left-hand value. Then to match this sign, the value of x must be negative so that the right-hand side becomes positive as well.)
Part 2: The distance from the vertex to the directrix is given by c. This equation has its vertex at the origin (0, 0). If it opens to the left, the directrix is a vertical line to the right of the origin. This equation is y^2 = -4(1/2)x, so c = 1/2, and the directrix has the equation x = 1/2.
Part 3: The focus is inside the parabola, but it is the same distance from the vertex as the directrix. This distance is 1/2 units, and it will be to the left of the vertex. So the focus is at (-1/2, 0).
