Step-by-step explanation:

I think, he made a mistake because the exponents have different values but then if you'll look at his results, he just wrote the same thing. If you want, you could post the original problem, and I'll solve it for you :)
Answer with explanation:
The equation of two curves are
y=8 sin x
y=8 cos x
The point of intersection of two curves are
→8 sin x=8 cos x
sinx = cos x

When you will look between points , 0 and
,the curve obtained is right angled triangle.
Now, rotate the curve that is right angled triangle along the line , y= -1, to obtain a shape similar or resembling with Right triangular prism.
Draw a circular disc in the right triangular prism , having radius =x,and small part on the triangle having length dx.dx varies from 0 to
.
Required volume of solid obtained

=8-4√2 cubic units
To find out how much she spent during the second month, all we have to do is subtract $305.43 and $213.20
$305.43 - $213.20 = $92.23
Therefore she spent $92.23 during the second month
Hope this helps
Answer:
13
Step-by-step explanation: