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ntox101
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Homework Statement
a.) Find the area of the region bounded by the graphs of f(x) = 1/x and 2x+2y=5
b.) Also, use the shell method to setup the integral that represents the volume of the solid formed by revolving the region bounded by the two same graphs about the y= 1/2. (Do not evaluate the integral)
Homework Equations
For area between two curves : Integral[f(x) - g(x)] dx (depending on which curve is on top)
For shell method : 2pi Integral[ p(x) h(x) ] dx
The Attempt at a Solution
a.) What I did was take the second equation (2x+2y=5) and solved for y to make (y = (5-2x)/2). I then made Integral[ ((5-2x)/2) - (1/x) ] dx. For [a,b], I just used the zoom function on my calculator and got a = 1/2 and b = 2. (I'm not sure if it is correct or not) After integrating, I got 1/2[5x-x2-ln|x|]
b.) I haven't been able to get this setup to the way that I think is correct. My answer is
2pi Integral[ ( (5-2y)/2 ) * (2- (1/y)) ] dy . (with a = 1/2 and b = 2). I think my [a,b] are wrong because this is in terms of y, not x, since we are revolving around the y-axis.
Also, without using Mathematica, how can I use the Integrand symbols to make this look more presentable?
Thanks,
Jon
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