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Timske

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y = x + 2 , the volume is bounded by x = 0 and x = 2

v = pi*int x + 2
= pi [ x^2/2 + 2x]

sub in 2 and 0

= pi [(2^2/2 + 2(2)) ] - [(0^2/2 + 2(0) ]
= pi [2 + 2] - 0
= 4 pi cubic units

oops meant to be 2 + 4 = 6
so its 6pi
 
Last edited:

deswa1

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<a href="http://www.codecogs.com/eqnedit.php?latex=V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x@plus;2)^2dx \\V=\pi\int_{0}^{2}x^2@plus;4x@plus;4dx\\ V=\left [ \frac{x^3}{3}@plus;2x^2@plus;4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x+2)^2dx \\V=\pi\int_{0}^{2}x^2+4x+4dx\\ V=\left [ \frac{x^3}{3}+2x^2+4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" title="V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x+2)^2dx \\V=\pi\int_{0}^{2}x^2+4x+4dx\\ V=\left [ \frac{x^3}{3}+2x^2+4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" /></a>
 

deswa1

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y = x + 2 , the volume is bounded by x = 0 and x = 2

v = pi*int x + 2
= pi [ x^2/2 + 2x]

sub in 2 and 0

= pi [(2^2/2 + 2(2)) ] - [(0^2/2 + 2(0) ]
= pi [2 + 2] - 0
= 4 pi cubic units

oops meant to be 2 + 4 = 6
so its 6pi
You made a mistake in your first line. It should be the integral of (x+2)^2 not (x=2)
 

umm what

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thanks brahh :)
<a href="http://www.codecogs.com/eqnedit.php?latex=V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x@plus;2)^2dx \\V=\pi\int_{0}^{2}x^2@plus;4x@plus;4dx\\ V=\left [ \frac{x^3}{3}@plus;2x^2@plus;4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x+2)^2dx \\V=\pi\int_{0}^{2}x^2+4x+4dx\\ V=\left [ \frac{x^3}{3}+2x^2+4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" title="V=\pi\int_{0}^{2}y^2dx\\ V=\pi\int_{0}^{2}(x+2)^2dx \\V=\pi\int_{0}^{2}x^2+4x+4dx\\ V=\left [ \frac{x^3}{3}+2x^2+4x \right ]^{2}_{0}\\ V=\frac{56\pi}{3}" /></a>
 

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