Finding the Minimum Hypotenuse of a Right Angled Triangle | Hypotenuse Homework

  • Thread starter Thread starter cpashok
  • Start date Start date
  • Tags Tags
    Minima
Click For Summary

Homework Help Overview

The discussion revolves around finding the minimum value of the hypotenuse in a right-angled isosceles triangle, given two perpendiculars drawn from a point on the hypotenuse to the triangle's sides. Participants explore the relationship between the hypotenuse and the perpendiculars, a and b.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants attempt to express the hypotenuse in terms of a single variable, considering trigonometric relationships, but encounter difficulties in eliminating variables. Some question the validity of the problem setup, suggesting that the hypotenuse may not depend on a and b as initially thought.

Discussion Status

The discussion includes attempts to clarify the problem statement and explore various interpretations. Some participants express confusion regarding the relationship between the hypotenuse and the perpendiculars, while others suggest that the question may have been misinterpreted. A revised question is later introduced, indicating a potential shift in focus.

Contextual Notes

There is mention of a misunderstanding regarding the nature of the triangle and the problem's requirements, leading to a clarification about the actual question related to maximum length rather than minimum. This highlights the importance of accurate problem statements in mathematical discussions.

cpashok
Messages
12
Reaction score
0

Homework Statement


a and b are two perpendiculars drawn to the sides from a point on the hypotenuse of a right angled, isoceles triangle.

Find the minimum value of the hypotenuse in terms of a and b.

Homework Equations


ABC is a right angled, isoceles triangle, with AC, the hypotenuse, h.

X is a point on AC, from which the perpendiculars a and b are drawn to the sides AB and BC respectively.

AB = BC= h / (sq.root 2)


The Attempt at a Solution


Tried to represent h in terms of a single variable (some angle theta and trigonometric ratios of theta). This would eliminate two variables a and b. With this, h can be differentiated and equated to zero for Minima, and confirming it with 2nd derivative. But could not manage eliminating a and b and converting to a single variable equation.
 

Attachments

  • Maths.GIF
    Maths.GIF
    1.2 KB · Views: 637
Physics news on Phys.org
cpashok said:

Homework Statement


a and b are two perpendiculars drawn to the sides from a point on the hypotenuse of a right angled, isoceles triangle.

Find the minimum value of the hypotenuse in terms of a and b.

Homework Equations


ABC is a right angled, isoceles triangle, with AC, the hypotenuse, h.

X is a point on AC, from which the perpendiculars a and b are drawn to the sides AB and BC respectively.

AB = BC= h / (sq.root 2)


The Attempt at a Solution


Tried to represent h in terms of a single variable (some angle theta and trigonometric ratios of theta). This would eliminate two variables a and b. With this, h can be differentiated and equated to zero for Minima, and confirming it with 2nd derivative. But could not manage eliminating a and b and converting to a single variable equation.

Since this is an isosceles right triangle, theta = pi/4, which it doesn't seem you have used. I don't know whether this is a helpful clue.
 
Mark44 said:
Since this is an isosceles right triangle, theta = pi/4, which it doesn't seem you have used. I don't know whether this is a helpful clue.

Hi! Thanks for your time. I was not referring to theta as angle BAC or BCA, which is pi/4. For a point X, a and b are fixed, and are related (except that I am unable to figure it out straight). If I can represent h as an equation of a alone, or b alone, or some other variable theta on which a and b are dependent, then I can differentiate h and equate to 0 for Minima. This is where I am stuck. Or, is there some other way?
 
Why is the attachment pending approval?
why is my question being unanswered?
Believe me i tried my best before posting up the question here.
Somebody please help me?
 
cpashok said:
Why is the attachment pending approval?
All attachments are screened by site admin before they are approved to be hosted at PF. This sometimes takes days, so it is quicker for you to host the image file at a free hosting site like imageshack.us and simply post a link to the image.

why is my question being unanswered?

Until we can view your attached file, we have no way of knowing where your mistakes might be.
 
cpashok said:

Homework Statement


a and b are two perpendiculars drawn to the sides from a point on the hypotenuse of a right angled, isoceles triangle.

Find the minimum value of the hypotenuse in terms of a and b.

This question doesn't make sense to me; the length of the hypotenuse doesn't actually depend on 'a' and 'b', so it can't be minimized with respect to those variables.

Are you sure the question isn't "Find the minimum length of the line segment AX in terms of a and b"?

Is there more to the question than what you have posted here?
 
gabbagabbahey said:
This question doesn't make sense to me; the length of the hypotenuse doesn't actually depend on 'a' and 'b', so it can't be minimized with respect to those variables.

Yes you're right. I went to school today and got the question sorted out, it wasn't isosceles. A friend of mine verbally stated out the question he had picked up from some guide book, and I seem to have taken it down wrongly, mixed up multiple questions!

Sorry about that. I panicked as I had an exam today!

The correct question is:

A point on the hypotenuse is at a distance a and b from the sides of the triangle. show that the maximum length of hypotenuse is (a^(2/3) +b^(2/3))^(3/2).

btw, i had this question on the exam and i solved it correctly.

I sincerely apologize for this mistake once again.
Thanks for your help.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 24 ·
Replies
24
Views
4K
Replies
5
Views
2K
  • · Replies 17 ·
Replies
17
Views
11K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
2
Views
2K