Step-by-step explanation:
area of rrctangle:
12×8= 96cm²
now if rectangle dissapears and then we "glue" what's left, we gonna get two circles
area of circle which gas diameter of 12cm( so radius will be 6cm)will be
πr²=36π≈113.04
another circles radius is 4cm,so area is:
16π≈50.25
sum of all areas: S≈96+113.04+50.25≈259.28cm2
Assuming this question is trying to enquire as to how many bottle of
water there are in each case, you simply need to divide 162 by 9 to find
the answer, which is that there are 18 bottles of water in each case.
Answer:
647.0625
Step-by-step explanation:
<span>since sin and cos = each other at pi/4; take your integrals from 0 to pi/4
</span><span>[S] cos(t) dt - [S] sin(t) dt ;[0,pi/4]
</span>
<span>to revolve it around the x axis;
we do a sum of areas
[S] 2pi [f(x)]^2 dx
</span>
<span>take the cos first and subtract out the sin next; like cutting a hole out of a donuts.
</span><span>pi [S] cos(x)^2 dx - [S] sin(x)^2 dx ; [0,pi/4]
</span>
<span>cos(2t) = 2cos^2 - 1
cos^2 = (1+cos(2t))/2
</span>
<span>1/sqrt(2) - (-1/sqrt(2) +1)
1/sqrt(2) + 1/sqrt(2) -1
(2sqrt(2) - sqrt(2))/sqrt(2) = sqrt(2)/sqrt(2) = 1</span>
9514 1404 393
Answer:
Step-by-step explanation:
If we let x and y represent the costs of a lamp and end table, respectively, the two purchases can be written as ...
3x +2y = 520
2x -y = 20
__
These equations can be solved many ways. If we use "elimination", we can add twice the second equation to the first to eliminate y:
(3x +2y) +2(2x -y) = (520) +2(20)
7x = 560 . . . . simplify
x = 80 . . . . . . divide by 7
y = 2x -20 = 2(80) -20 = 140
The cost of a lamp is $80; the cost of an end table is $140.
