Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
Puzzle: Who can spot what is wrong here?
Theorem: 4 = 5
Proof: 20 = 20
16  36 = 25  45
4^2  (9x4) = 5^2  (9x5)
4^2  (9x4) + 81/4 = 5^2  (9x5) + 81/4
(4  9/2)^2 = (5  9/2)^2
4  9/2 = 5  9/2
4 = 5
 one year ago
 one year ago
Puzzle: Who can spot what is wrong here? Theorem: 4 = 5 Proof: 20 = 20 16  36 = 25  45 4^2  (9x4) = 5^2  (9x5) 4^2  (9x4) + 81/4 = 5^2  (9x5) + 81/4 (4  9/2)^2 = (5  9/2)^2 4  9/2 = 5  9/2 4 = 5
 one year ago
 one year ago

This Question is Closed

lgbasalloteBest ResponseYou've already chosen the best response.0
how did you get 20=20 from 4=5
 one year ago

asnaseerBest ResponseYou've already chosen the best response.0
The Theorem states 4 = 5 It is then followed by the proof
 one year ago

asnaseerBest ResponseYou've already chosen the best response.0
and what exactly is wrong with that step?
 one year ago

FreyesBest ResponseYou've already chosen the best response.3
The step is squaring a negative 1/2 and the other is squaring 1/2
 one year ago

asnaseerBest ResponseYou've already chosen the best response.0
which is fine, since (1/2)^2 = (1/2)^2
 one year ago

FreyesBest ResponseYou've already chosen the best response.3
Yes but then the square root of that after is where the problem is
 one year ago

FreyesBest ResponseYou've already chosen the best response.3
you're choosing the positive side
 one year ago

FreyesBest ResponseYou've already chosen the best response.3
not the same negative part you're squaring
 one year ago

asnaseerBest ResponseYou've already chosen the best response.0
it is essentially the same as saying: (1)^2 = (1)^2 therefore 1 = 1
 one year ago

oldrin.batakuBest ResponseYou've already chosen the best response.0
\[\pm[4\frac92]=\pm[5\frac92]\]
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.