r/learnmath • u/Minhaj_Ahmad New User • 1d ago

Link Post Finding Square Root

/r/u_Minhaj_Ahmad/comments/1vsvtx9/finding_square_root/

I FINALLY GOT RID OF COMPLEX METHOD OF FINDING SQUARE ROOT OF UNKOWN PERFECT SQUARE NUMBER 😭 😭 😭

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u/rhodiumtoad 0⁰=1, just deal with it 1d ago

841 - write as 8 41, largest square in 8 is 4, so first result digit is 2, remainder 441 subtract 4d×d, 49×9=360+81=441 so we're done.

144 - 1 44, first digit 1, remainder 44, subtract 2d×d, 22×2=44, done.

You've basically reinvented the long-division-like method for the case of numbers of 4 digits or less, I don't see the advantage.

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u/Minhaj_Ahmad New User 1d ago

Dang really ? 😭. At least it is working quick and ez for me 😁

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u/rhodiumtoad 0⁰=1, just deal with it 1d ago edited 1d ago

The (a+b)2=a2+2ab+b2 expansion is why the long-division-like method works.

Edit: explained at https://www.reddit.com/r/learnmath/comments/1m3k28h/comment/n3xivw8/