Finding the Intersection of Two Graphs: Exact Solutions and Integrals

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Homework Help Overview

The discussion revolves around finding the intersection points of the graphs of the functions y = tan(x) and y = x^(1/3). The original poster expresses a desire for an exact solution but encounters difficulties in achieving this.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss setting up integrals related to the area between the curves and question the feasibility of finding exact solutions. There is mention of wanting to avoid using arctan and concerns about the existence of closed-form solutions.

Discussion Status

Some participants are exploring the setup of integrals for calculating volumes generated by rotating the area between the curves. There is a recognition that numerical methods may be necessary due to the complexity of the equations involved. Multiple interpretations of how to represent the integrals and upper limits are being discussed.

Contextual Notes

There are constraints regarding homework requirements, such as needing to set up integrals without evaluating them and specifying upper limits for the integrals. The original poster is also facing challenges with the expectations set by their instructor regarding decimal representations.

Jbreezy
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Homework Statement



Hi I'm trying to find where these two graphs intersect I would like it to be exact but it isn't quite working.
If I have y = tan(x) and y = x^1/3 how can I solve exactly?

Homework Equations



tan(x) = x^1/3 ? Hmm.
I'm not sure. I don't want arctan popping up on the right side. So I don't know really.

The Attempt at a Solution

 
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Jbreezy said:

Homework Statement



Hi I'm trying to find where these two graphs intersect I would like it to be exact but it isn't quite working.
If I have y = tan(x) and y = x^1/3 how can I solve exactly?

Homework Equations



tan(x) = x^1/3 ? Hmm.
I'm not sure. I don't want arctan popping up on the right side. So I don't know really.

The Attempt at a Solution


Show your work.
 
I'm supposed to just set up the integral not evaluate it. They want me to consider y = tanx and y = x^1/3 in the first quadrant.
Rotated about x I have:
V = 2PI (integral) x(tanx-x^1/3) dx
Between what ever result I get for the intersection of 0 and tanx = x^1/3
and for about y I have
V = 2PI( integral) y(arctan(y) - y^3) dy
Between 0 and whatever y^3 = arctan(y) intersections is.
 
This is my work
tan(x) = x^1/3
x = arctan(x^1/3) ok ... now I'm stuck
 
Jbreezy said:
This is my work
tan(x) = x^1/3
x = arctan(x^1/3) ok ... now I'm stuck

That's because there is (very probably) no closed-form solution; just use a numerical method.
 
What do you mean a numerical method and how am I supposed to indicate the upper bound my teacher gives 0's for decimals. Also does my integrals look OK?
 
Do my integrals look set up properly? Also how am I supposed to write an upper limit? Like integral from 0 to
tan(x) = x^1/3? Because I can't really solve this but I have to represent it exactly.
 

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