(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:The answer B: (x – 2)² + (y + 8)² = 121
Step-by-step explanation:
Just took the test on edge
Answer:
Step-by-step explanation:
Use the slope-intercept formula: 
where m is slope and b the y-intercept.
Use the slope formula for when you have two points:
Rise over run is the change in the y-axis over the change in the x-axis. Insert values:
Simplify parentheses (negative+negative=positive)
Simplify
2 is the slope:
Now use one of the points to find the y-intercept by substituting the x and y values into the equation. Solve for b:
(4,7)
The y-intercept is -1. Insert into the equation. Change the + symbol to -:
Done.
the number is 100
Step-by-step explanation:
1/4 of hundred = 25
2/4 of hundred = 50
3/4 of hundred = 75
4/4 of hundred = 100
Answer:
f(x) = -2x² - 8x - 2
General Formulas and Concepts:
- Order of Operations: BPEMDAS
- Expand by FOIL (First Outside Inside Last)
- Standard Form: f(x) = ax² + bx + c
- Vertex Form: f(x) = a(bx + c)² + d
Step-by-step explanation:
<u>Step 1: Define function</u>
Vertex Form: f(x) = -2(x + 2)² + 6
<u>Step 2: Find Standard Form</u>
- Expand by FOILing: f(x) = -2(x² + 4x + 4) + 6
- Distribute -2: f(x) = -2x² - 8x - 8 + 6
- Combine like terms (constants): f(x) = -2x² - 8x - 2
