(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
4d = 1/3
d = 1/3/4
d = 1/12
Thus, c is the correct choice.
Answer:
sorry i dont
Step-by-step explanation:
If
has to be a solution of the equation, just plug it in:
![(\pm 15i)^2 + [1] = 0 \iff -225 + [1] = 0 \iff [1] = 225](https://tex.z-dn.net/?f=%20%28%5Cpm%2015i%29%5E2%20%2B%20%5B1%5D%20%3D%200%20%5Ciff%20-225%20%2B%20%5B1%5D%20%3D%200%20%5Ciff%20%5B1%5D%20%3D%20225%20)
So, the solutions of
are