Find the value of k for the integral

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Homework Help Overview

The problem involves finding the value of k such that the area under the curve f(x) = sqrt(x + 2), bounded by the x-axis and the line x = 2, is divided into two equal areas by the line x = k.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the setup of the integral to find k, with one noting confusion about incorporating x = k into the area calculations. Another participant suggests that k should satisfy the equality of two definite integrals representing the areas.

Discussion Status

The discussion is progressing with participants exploring the relationship between k and the areas under the curve. Some guidance has been provided regarding the setup of the integrals, and there appears to be a shared understanding of the approach needed to find k.

Contextual Notes

There is mention of the need to find k that results in equal areas, but the exact method for achieving this remains under exploration. The original poster expresses uncertainty about the correct approach to take.

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Homework Statement


Find the value of k so that the region enclosed by f(x)=sqrt(x+2), the x-axis, and the line x=2 is divided by x = k into two regions of equal area.



Homework Equations


definite integral properities, fundamental theorem of calculus



The Attempt at a Solution


I have no problem finding the integral for this area, I'm just confused over the last part of the question and the use of the line x = k. How am I supposed to bring this into the answer to find the value of k that makes the area two equal regions? I had an idea to sub k in for x, but this doesn't appear to be anywhere near the right method. Any help with this question would be greatly appreciated, thanks in advance.
 
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You want to find k so that
[tex]\int_{-2}^k \sqrt{x + 2} dx = \int_k^2 \sqrt{x + 2}dx[/tex]

By observation, it looks like k will be somewhere around 1/2.
 
Ahh thanks for that Mark, I see how to do it now, and the answer is actually a weird decimal that in exact form is 2(cuberoot2 - 1).
 
Emethyst said:
Ahh thanks for that Mark, I see how to do it now, and the answer is actually a weird decimal that in exact form is 2(cuberoot2 - 1).
Which to two decimal places is .52, so my guess was pretty close!
 

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