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Math Tricks of equating 1=0

Whats possibly wrong in this equation.. have seen these stuffs when I was small but why isn't it correct ?

9 = (-3)^2

9 = (3)^2

accordingly, (-3)^2 = (3)^2 => -3 = 3 => 6 = 0 and hence infinite solutions arise after this showing n=0 for all n belonging to real numbers. :P

Note by Tunir Saha
4 years, 3 months ago

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the fallacy here is that the rule of taking the root of an equation only holds true when both numbers are positive, which -3 is not. Therefore, algebra continues to hold true.

This is a useful website for these types of problems http://en.wikipedia.org/wiki/Mathematical_fallacy Gaurav Sharma · 4 years, 3 months ago

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@Gaurav Sharma Lol. Wikipedia is a "useful" site. only americans Justin Wong · 4 years, 3 months ago

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We know that while taking roots we have to take modulus on both the sides i.e. (in this problem) after (-3)^ 2 =(3)^ 2
|-3| =|3|

which gives us 3=3 which is always true Anshul Agarwal · 4 years, 3 months ago

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When taking square root...be careful to take modulus on both sides...which gives u 3=3!! Tanya Gupta · 3 years, 5 months ago

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