(a) See the attached sketch. Each shell will have a radius <em>y</em> chosen from the interval [2, 4], a height of <em>x</em> = 2/<em>y</em>, and thickness ∆<em>y</em>. For infinitely many shells, we have ∆<em>y</em> converging to 0, and each super-thin shell contributes an infinitesimal volume of
2<em>π</em> (radius)² (height) = 4<em>πy</em>
Then the volume of the solid is obtained by integrating over [2, 4]:
(b) See the other attached sketch. (The text is a bit cluttered, but hopefully you'll understand what is drawn.) Each shell has a radius 9 - <em>x</em> (this is the distance between a given <em>x</em> value in the orange shaded region to the axis of revolution) and a height of 8 - <em>x</em> ³ (and this is the distance between the line <em>y</em> = 8 and the curve <em>y</em> = <em>x</em> ³). Then each shell has a volume of
2<em>π</em> (9 - <em>x</em>)² (8 - <em>x</em> ³) = 2<em>π</em> (648 - 144<em>x</em> + 8<em>x</em> ² - 81<em>x</em> ³ + 18<em>x</em> ⁴ - <em>x</em> ⁵)
so that the overall volume of the solid would be
I leave the details of integrating to you.
Answer:
graph A
Step-by-step explanation:
When looking at a graph, there are two different axes. The vertical values--marked by the center up/down line--are "y-values"; and this is called the "y-axis"
The horizontal values--marked by the left/right line--are "x-values"; and this is called the "x-axis"
For the x-axis, values to the left side of the origin (the place where the y-axis and x-axis intercept) are smaller than 0--they are all negative values.
Values to the right side of the origin are positive--greater than 0.
For the y-axis, positive numbers are on the top half [once again, the midpoint / 0 is where the two lines are both = to 0; the origin] and negative numbers are on the bottom half.
Ordered pairs (points) are written as (x,y)
(x-value, y-value)
We are looking for a graph that decreases (along the y-axis), hits a point below the origin, and goes flat/stays constant.
When a graph is decreasing (note: we read graphs from left to right), the line of the graph is slanted downwards (it looks like a line going down).
So, if we look at the graphs, we can see Graph A descending, crossing the y-axis {crossing the middle line /vertical line / y-axis} at a value of -7, and then staying constant (it is no longer increasing or decreasing because the y-values stay the same)
hope this helps!!
Answer:
It comes from correct solution steps and is not a valid solution of the equation.
Step-by-step explanation:
Answer: what
Step-by-step explanation:
So if we want to know the common solution(s) to a system of 2 equations, So we can just set both equations equal to each other and solve for the x value(s). That’s where I start below;
2x^2-13x+21 = 2x^2+9x-56
2x^2 cancels out and moving everything to one side and anything with an x variable to the other side we have then;
-22x=-77
22x=77 by cancelling the negative signs
x=77/22 therefore x=7/2 or 3.5
Hope this helps you. Any questions please ask.
