How do you findout square root of 40401?

Answer 1

If you are familiar with some basic squares, you may know that (x+2)2 = x2 + 4x + 4.

The coefficients here are 1,4,4 - not quite in the same order but pointing in the right direction.

From the above you may deduce that (2y+1)2 = 4y2 + 4y + 1

Better, but not quite there.

But you should also know that 22 = 4 so that 2002 =40000.

And then it should all fall into place:

40401 = (+/- 201)2

The simpler alternative is to use the square root function on your calculator!