Answer:
The correct answer B) The volumes are equal.
Step-by-step explanation:
The area of a disk of revolution at any x about the x- axis is πy² where y=2x. If we integrate this area on the given range of values of x from x=0 to x=1 , we will get the volume of revolution about the x-axis, which here equals,
which when evaluated gives 4pi/3.
Now we have to calculate the volume of revolution about the y-axis. For that we have to first see by drawing the diagram that the area of the CD like disk centered about the y-axis for any y, as we rotate the triangular area given in the question would be pi - pi*x². if we integrate this area over the range of value of y that is from y=0 to y=2 , we will obtain the volume of revolution about the y-axis, which is given by,
If we just evaluate the integral as usual we will get 4pi/3 again(In the second step i have just replaced x with y/2 as given by the equation of the line), which is the same answer we got for the volume of revolution about the x-axis. Which means that the answer B) is correct.
9514 1404 393
Answer:
66 cm²
Step-by-step explanation:
The area of the polygon is the sum of the areas of the triangle and the rectangle it sits on. The dimensions of the triangle can be found by examining the top/bottom dimensions shown and the left/right dimensions shown.
The width (base) of the triangle is the difference between the lengths of the bottom and top horizontal lines: (12 -9) cm = 3 cm.
The height of the triangle is the difference between the lengths of the left and right sides of the figure: (9 -5) cm = 4 cm.
The dimensions of the rectangle are shown a the bottom and the left sides of the figure.
triangle area = 1/2bh = 1/2(3 cm)(4 cm) = 6 cm²
rectangle area = LW = (12 cm)(5 cm) = 60 cm²
Total polygon area = 6 cm² + 60 cm² = 66 cm²
First, third, fifth, and sixth answer
They created ratios so people could get information.
Answer:
1. 75 minutes
2. 5:50
Step-by-step explanation:
you have to add and subtract