Answer:
radius is 4 height is 10 volume is 167.55
Step-by-step explanation:
Answer:
The area of the sector is 3pi/2
Step-by-step explanation:
A sector is that part of a circle bounded by 2 radii and an arc
The circle has an area of 9 pi with a central angle of 60 degrees.
Now the area of the sector is pretty much straight forward to calculate. Since it is a circle, the total angle we have is 360.
Now the sector subtends an angle of 60 degrees at the centre. What this means is that the sector is exactly 1/6 of the circle. meaning that cutting the circle into 6 slices will give the sector.
Thus, the area of the sector is one-sixth the area of the circle.
The area of the sector is thus 1/6 * 9pi = 9pi/6 = 3pi/2 or 3/2 pi
F(x) = 18-x^2 is a parabola having vertex at (0, 18) and opening downwards.
g(x) = 2x^2-9 is a parabola having vertex at (0, -9) and opening upwards.
By symmetry, let the x-coordinates of the vertices of rectangle be x and -x => its width is 2x.
Height of the rectangle is y1 + y2, where y1 is the y-coordinate of the vertex on the parabola f and y2 is that of g.
=> Area, A
= 2x (y1 - y2)
= 2x (18 - x^2 - 2x^2 + 9)
= 2x (27 - 3x^2)
= 54x - 6x^3
For area to be maximum, dA/dx = 0 and d²A/dx² < 0
=> 54 - 18x^2 = 0
=> x = √3 (note: x = - √3 gives the x-coordinate of vertex in second and third quadrants)
d²A/dx² = - 36x < 0 for x = √3
=> maximum area
= 54(√3) - 6(√3)^3
= 54√3 - 18√3
= 36√3.
The area of the semicircle is A = 1187.9 cm².
<h3>What is the area of a circle?</h3>
The area of a circle with a radius of r is A = πr².
Given that, the diameter of the semicircle is 55 cm.
The radius of the semicircle is,
r = 55/2
The area of a semicircle is given by,
A = (1/2)πr²
Substitute the values,
A = (1/2)π(55/2)²
A = 1187.9
Hence, the area of the semicircle is A = 1187.9 cm².
Learn more about the area of a circle:
brainly.com/question/22964077
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