You can
put this solution on YOUR website!
this is either visualised as

or as

. The second is easier to work with, since

is a big number, whereas

is small...so easier, in my opinion.

means what is the number "a" such that a*a*a*a=4? You should LEARN this sort of thing.
Hopefully you will know b if b*b=4? --> b is 2.
OK, so what about c*c=2? --> answer is
So,
-->

. Check it on your calculator.
So we have
jon.