Mistake in provided solutions?

  • Thread starter Thread starter unscientific
  • Start date Start date
  • Tags Tags
    Mistake
Click For Summary

Homework Help Overview

The problem involves evaluating an integral, with participants discussing the correctness of variable substitutions in the provided solutions. The subject area pertains to calculus, specifically integration techniques.

Discussion Character

  • Conceptual clarification, Assumption checking, Mixed

Approaches and Questions Raised

  • Participants are examining the validity of variable substitutions in the integral, questioning whether the substitutions made in the working are correct. There are differing interpretations of which variable the first integral is with respect to, and some participants are comparing their results after integrating in different orders.

Discussion Status

The discussion is active, with participants offering differing perspectives on the substitutions and integration order. Some guidance has been provided, as one participant acknowledges a mistake after receiving feedback, indicating a productive exchange.

Contextual Notes

There appears to be confusion regarding the variable of integration and the resulting answers, with participants noting discrepancies in their results and assumptions about the problem setup.

unscientific
Messages
1,728
Reaction score
13

Homework Statement



The problem is attached in the picture.


The Attempt at a Solution



If you refer to line 2 of the working, they substituted x with 'b' instead of y with 'b' since the first integral is with respect to y.

Is this a mistake or is there something more?
 

Attachments

  • solution1.jpg
    solution1.jpg
    21.7 KB · Views: 466
Physics news on Phys.org
Looks to me like they're substituting x=a and x=0 on line 2, just like you'd expect.
 
The first integral is NOT with respect to y, it is with respect to x.
 
I got a different answer when I integrated with respect to y first... I am missing the additional sqrt(b) term..
 
Then you made a mistake somewhere :-)
 
clamtrox said:
Then you made a mistake somewhere :-)

You are right, I saw my mistake.. Thanks btw!
 

Similar threads

Solving a linear differential equation with constant coefficients
  • · Replies 9 ·
Replies
9
Views
3K
Solving a Problem: Have I Made a Mistake or Are the Solutions Wrong?
  • · Replies 4 ·
Replies
4
Views
1K
Is this the correct general solution of the given PDE?
  • · Replies 12 ·
Replies
12
Views
2K
Finding the Radius of Convergence for Y=6x+16 - Troubleshooting and Solution
  • · Replies 4 ·
Replies
4
Views
2K
Integration. Where is the mistake? (if there is)
  • · Replies 3 ·
Replies
3
Views
2K
Center of mass of spherical shell inside of cone (Apostol Problem).
  • · Replies 3 ·
Replies
3
Views
2K
The below solution seems to assume that 1/0 = 0
  • · Replies 7 ·
Replies
7
Views
2K
Finding the Expression for v Using Partial Integration
  • · Replies 4 ·
Replies
4
Views
1K
How should I show that ## B ## is given by the solution of this?
  • · Replies 2 ·
Replies
2
Views
1K
Proving stability of linear system equations
  • · Replies 2 ·
Replies
2
Views
1K