Maths. Surds. Help.

Two example problems.

The squiggly lines are square root. The power is 2 in both cases.

Is it possible to explain those two ‘sums’ ? I am finding them incomprehensible.

18 thoughts on “Maths. Surds. Help.

  1. I haven’t tried this out yet but here goes:

    1. Find the square root of 2 and 8. Add the answers together and multiply this second answer by itself. This should equal 18.

    2.(Part 1) Find the square root of 3. Take the answer away from 2 and multiply this second answer by itself. I’ll call that A.
    (Part 2) Find the square root of 3. Multiply that by 4 and subtract the answer from 7. I’ll call that b.
    If the equation is correct then A should be equal to B.

    I’ll go try them and see if they work now :)

  2. I suppose it was a test that asking you to insert some math symbols will make the sums correct, right ?
    If you try to calculate them with a calculator you will see that the square root of 2 plus the square root of 8, all at the power of 2 give you 18. I suppose the other it’s a the same.

    Maybe i’m missing what is your real question.

  3. David on 13:28 Thursday 8 Dec 2005 at 13:28 Thursday 8 Dec said:

    (a+b)^2 = a^2 + b^2 + 2ab

    (SQR(2)+sqr(8))^2 = 2+8+2*(sqr(2)*sqr(8)), but sqr(8) = 2*sqr(2)
    so 2+8+2*(sqr(2)*sqr(8)) = 2+8+2(sqr(2)*2*sqr(2)) = 10+2*(4)
    = 18

    (a-b)^2 = a^2+b^2-2ab
    => (2-sqr(3))^2 = 4+3-2*2*sqr(3) = 7-4*sqr(3)

    Sorry for poor english, i’m from Russia
    bravo:)) i was afraid that nobody will remebered this school rule. It’s the elementary case of using Isaak Newton(right or no?) binom

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