Practice question

There was an explanation by GregMat and when he squares it there comes a 2 can anyone explain in detail…

How did you get 2 everytime you square it? Please explain. Thanks

If you square the left hand side once you get the following:

If you square that again the middle term will again give you a 2.

1 Like

You can either use (a+b)^4 = a^4+b^4+4a^3b+4ab^3+6a^2b^2 \tag{1}
or
((a+b)^2)^2= (a^2+b^2+2ab)^2= (a^2)^2+(b^2)^2+(2ab)^2+2(a^2)\times(2ab)+ 2(2ab)\times(b^2)+ 2(a^2)\times(b^2)\tag{2}

Equation 1 = Equation 2

Got it. Thanks