Jump to content
BrainDen.com - Brain Teasers
  • 0

impossible result


Question

3 answers to this question

Recommended Posts

  • 1
Spoiler

The error happens when he takes the square root of both sides.

(4-9/2)^2 = (-1/2)^2 = (1/2)^2 = (5-9/2)^2

Or more simply...

(-1)^2 = (1)^2, take the square root of both sides gives -1 = 1.  Except it doesn't!

sqrt((-1)^2) = |-1| = |1| = sqrt(1^2)

 

  • Upvote 1
Link to post
Share on other sites
  • 0
Spoiler

so you cant say that just because X2 = Y2, X = Y, that would be theoretically incorrect. X2 = Y2 implies that X = |Y| where |a|  or mod(a) denotes +/-a. From there we eliminate the absurdity and only consider the solution for the equation that makes sense

 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...