The answer is C you dived the circumference by 2 and use the formula for the area of a circle which is A = π × r^2
Answer:
a) 8π
b) 8/3 π
c) 32/5 π
d) 176/15 π
Step-by-step explanation:
Given lines : y = √x, y = 2, x = 0.
<u>a) The x-axis </u>
using the shell method
y = √x = , x = y^2
h = y^2 , p = y
vol = ( 2π ) 
=
∴ Vol = 8π
<u>b) The line y = 2 ( using the shell method )</u>
p = 2 - y
h = y^2
vol = ( 2π )
= 
= ( 2π ) * [ 2/3 * y^3 - y^4 / 4 ] ²₀
∴ Vol = 8/3 π
<u>c) The y-axis ( using shell method )</u>
h = 2-y = h = 2 - √x
p = x
vol = 
= 
= ( 2π ) [x^2 - 2/5*x^5/2 ]⁴₀
vol = ( 2π ) ( 16/5 ) = 32/5 π
<u>d) The line x = -1 (using shell method )</u>
p = 1 + x
h = 2√x
vol = 
Hence vol = 176/15 π
attached below is the graphical representation of P and h
You can say
x+y=5
x=5-y
You know the value of x, put it into the next equation.
3(5-y)-7y=19
15-3y-7y=19
15-19 = 10y
-4=10y
-4/10=y
-2/5=y
Put y value back into either equation to find value of x.
x+y=5
x-2/5=5
x=5+2/5
x=27/5
Therefore, x,y = (27/5, -2/5)
Hope I helped :)