Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Possible Duplicate:
The $3 = 2$ trick on Google+

I saw google some links

$$-6 = -6 $$

$$9-15 = 4-10 $$

adding $\frac{25}{4}$ to both sides:

$$9-15+ \Big(\frac{25}{4} \Big) = 4-10+ \Big(\frac{25}{4} \Big) $$

(This is just like : $a^2 – 2ab + b^2 = (a-b)^2$.)

Here $a = 3$, $b=\frac{5}{2}$ for L.H.S., and $a =2$, $b=\frac{5}{2}$ for R.H.S.

So it can be expressed as follows:

$$ \Big(3-\frac{5}{2} \Big)^2 = \Big(2-\frac{5}{2}\Big)^2 $$

Taking positive square root on both sides:

$$ 3 - \frac{5}{2} = 2 - \frac{5}{2} $$

$$ 3 = 2 $$

but not clear. Can anybody help me?

Thanks in advance !!!

share|cite|improve this question

marked as duplicate by Rasmus, J. M., VelvetThunder, David Mitra, yunone Dec 3 '11 at 12:25

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Note: $\displaystyle {\sqrt[n]{a^n} = |a|}$, if $n$ is even and square root is $n=2$.

So, $$2− \frac52=-\frac{1}{2}$$ is not a positive square root making your assumption, and hence, the entire proof, flawed.

share|cite|improve this answer
but how to proof Ramanujam's? – anglimass Dec 3 '11 at 12:17
@anglimass:I don't understand. Please rephrase your question. – VelvetThunder Dec 3 '11 at 12:18

Not the answer you're looking for? Browse other questions tagged or ask your own question.