r/Indianmathnerds

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Finding Square Root

Finding square root of a number that I don't know was a pain for me.

Using that long division method 😭.

Like 841 it's the square root of 29, I didn't know that I tried many ways to over come but in the end I just used the calculator.

I was furious and curious can I find the square value of any number using (a+b)² expression then maybe I can also find the square root of perfect square numbers using it?

I came up with (10a+b)²= S [I know it's looks similar to that expression and actually it is I'm not claiming I found something new I just got rid of my problem]

100a²+20ab+b² = S (s is the targeted square value of which square root we are looking for.)

Now conditions; a= or < S, b can be only a single digit from 0 to 9.

Example: S=144.

100a²+20ab+b² =144

Then a=1 => 100+20b+b²=144

20b+b²=44

(For selecting b we can guess the number or just divide remaining number by 20a [a=1 in this case].)

44/20 ≈2

Now substituting as a test-

20(2)+(2)² =44

LHS = RHS then

a=1, b=2

(10×1+2)² =12².

I will do further case study related to this stuff.

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u/Minhaj_Ahmad — 18 hours ago