A supposed proof that 2 + 2 = 5 has been circulating. Can you see the error?
As common, watch the video for an answer.
Or hold studying.
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Reply To False Proof 2 Plus 2 Equals 5
(Just about all posts are transcribed shortly after I make the movies for them–please let me know if there are any typos/errors and I’ll appropriate them, thanks).
References
The error could be very early within the derivation, particularly the a part of the step stating:
4 – 9/2 = √((4 – 9/2)2)
The left-hand facet is the same as -1/2, whereas the correct hand facet is the same as 1/2.
In distinction, it’s true that:
5 – 9/2 = √((5 – 9/2)2)
Either side are equal to 1/2.
Many college students are confused why one equation is true however the different is just not.
Whereas squaring and taking the sq. root are inverse operations, they aren’t fully reversible steps. When you sq. an actual quantity, you all the time get a non-negative end result, so whenever you take the sq. root, you’ll find yourself with a non-negative quantity as nicely. So a damaging quantity that will get squared after which sq. rooted will find yourself as a optimistic quantity. The final rule is:
√(x2) = |x|
Right here’s one other perspective. So that the sq. root √x be a perform, it’s required that each x worth correspond to a singular output worth. So √4 should solely be equal to at least one worth, 2, moderately than each values 2 and -2. So in the event you take the sq. of a quantity, after which the sq. root, you’ll all the time find yourself with a non-negative worth. Should you began with a damaging quantity your end result will likely be its reverse.
So this false proof stumbles practically firstly. But its reputation demonstrates how many individuals get confused by the exact particulars of the sq. root perform.
References
Reddit
https://www.reddit.com/r/sciencememes/feedback/1gi7mz7/engineering_maths_be_like/
https://www.reddit.com/r/LinkedInLunatics/feedback/15v4ojm/what_is_even_the_point_of_this_post_by_a/
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