Start with
:
17 falls between the perfect squares of 16 and 25,
so
will fall between
and
, which is a funny way to say 4 and 5.
Now if that negative is really supposed to be there, then using the same logic,
will fall between -4 and -5.
The key is to find the two perfect square closest to what's under the radical.
For
:
156 fall between 144 and 169, so
falls between
and
, or 12 and 13. Again, same note if you really meant
.
For
:
Trying out some perfect squares:
We've found 225 and 256 are on either side of 249, so
falls between 15 and 16, again with the same note if you meant
.