(a) First find the intersections of

and

:

So the area of

is given by

If you're not familiar with the error function

, then you will not be able to find an exact answer. Fortunately, I see this is a question on a calculator based exam, so you can use whatever built-in function you have on your calculator to evaluate the integral. You should get something around 0.5141.
(b) Find the intersections of the line

with

.

So the area of

is given by


which is approximately 1.546.
(c) The easiest method for finding the volume of the solid of revolution is via the disk method. Each cross-section of the solid is a circle with radius perpendicular to the x-axis, determined by the vertical distance from the curve

and the line

, or

. The area of any such circle is

times the square of its radius. Since the curve intersects the axis of revolution at

and

, the volume would be given by
Answer:

Step-by-step explanation:
Surface area of cylinder = 2πr(h + r)
Volume of cylinder = πr²h
Given that S.A = Volume of the cylinder, therefore, we have:
2πr(h + r) = πr²h
Radius (r) is given as 2.5 cm
height (h) = x cm
Input the values and solve for x
2πr(h + r) = πr²h
2πr(h + r) = πr(rh)
2(h + r) = rh (πr cancels πr)


Subtract 2x from both sides


Divide both sides by 0.5



36.
Convert 10% to .1, (10 divided by 100)
then multiply 40 times .1
then subtract 4 by 40
=36
So find the area of each shape and add them.
30+30+30+30+36=156
Triangle A= 1/2xLxH
Square A= LxH